If thats a TPI 305 4.10 wont help much. Put a bigger cam and Efi throttle body, or a Carb, rpm edelbrok Manifold, port the heads and 305 will run with those 410's.
Everyone saying it's not worth it aren't paying attention. Notice the wheelspin at launch and into 2nd gear. He's putting a lot more torque on the ground. If you're already gutting the pumpkin, this is a no-brainer, 4.10 is a great upgrade but be sure to put in a posi unit so you can get the best traction. If this were a rolling start, he likely would have put down much better numbers due to better traction. Unless you have crazy low end torque or drive a ton of highway speed, go with the 4.10s. Camaro, truck, Suburban... Doesn't matter. I swapped my Suburban to 4.10s when the original diff bearings got worn, was the greatest improvement I've ever done, and NO it didn't mess up the fuel mileage. If anything I get better mileage around town, and less mileage at highway speeds. 3.08 is great if you're going for top end and already struggle to hook up. But for anything close to a stock vehicle that's a daily driver, 4.10s make it much more fun to drive.
Love it! Thanks for the stat line, that's was fun and nostalgic. Times were right on par with what I remember back in the late 80's. Don't listen to the haters the car is a product of its time and they were considered badass back then.
Ok, guys.. don't laugh! Lol... But I have a 71 Imperial with a lightly massaged 440;, cam, heads, .40 over. Built it to pull a camper while going to chrysler shows. It has a huge factory trans cooler. 8.75 rear with the 489 case. I went from the 2.76 gear to a 3.55. What a difference!! I know, I know... its a huge car and nobody cares. But, I love it. I think with the way the engine is built, the 3.55 is perfect for the torque curve and power band!
Wow, I was surprised how many experts showed up. I'm waiting for John Force next. Your music is a little over the top but aside from that, your ambition, time and expense to learn something and show it to the world is to be commended. Pretty good video. Keep on trying and don't be discouraged by people that would rather be negative than supportive.
Love the simple test, results, sped up install. Good way too see how your mods are coming. Side note, ignore the “slow, it’s a 305” comments. Not everyone has a cobra mustang or a corvette. Run what you have, have all the fun you can get
I got a 68 stang coupe with a wicked 347 stroker I built. Switched from the factory 8” with 3.00 gears to a 9” with 3.25s almost 20 years ago now. What a difference a 1/4 turn made! Now with this crazy stroker I’d love to go to like 3.89s or something around there. Gonna really wake that stroker up. I hardly ever drive her on the interstate so why not?! Lol
Too many shit talking couch mechanic douchebags in the comments! A true gear head enjoys all cars regardless of horsepower numbers, engines, or car brand! Also Rome wasn't built in a day! Good stuff
Thank you for restoring my faith in these comments, everyone's like your so slow just do this or do that, like everyone has 10k to drop on their car. As David Freiburger says dont get it right get it running.
This is a great example of why it's valuable to get hard data to determine shift points. It probably felt better to not rev out 2nd with the shorter gears, but in reality, it probably would've maintained it's 1/2 second lead that it had to 60mph if you'd have ran 2nd out to the same RPM as you did with the taller gears. This also highlights the problem with stock stall speed's on 3/4/5 speed transmissions; the shift recovery is terrible from such giant gap during shifts. Put a 2,800 or 3k stall in this thing, and put some more cam timing in it PLEASE.
I had a 91 Mustang GT,5speed, with 2.73's, went to 3.73's, what a difference. Then went to 4.10's, man, what a wakeup. Gears will give more than most for the money
Had a black '88. The sound of a 5.0 rumbling by on Flowmasters always puts a smile on my face. Loved that car no matter how many times it tried to kill me.
Thats really interesting, I guess to make the 4.10s work you need to do some mods to the engine. I am surprised by the 60ft times but the 0-60mph justifies the swap. On the street quarter mile means nothing it is your times for 0-40, 0-50 and 0-60 that you feel and these improved 1/2 a second and a nice chirp when you hit second gear too.
I had the exact same setup in High School but minewas in an 86 IROC Z…after the 4:10’s I shred the transmission/torque arm mount almost every weekend!👍🏻
Hey pretty cool! Back in the 90's I had a 83 Firebird with 383 stroker and Richmond 4:10 posi. It's roastin'em here in my car list. It had a 400sbc and 700R4 when I got it but quickly spun a bearing so we put a $150 350 and swapped the heads over. I shattered the spider gears and cracked the flex plate performing another sweet sick dope Rockford turn so it got the used Richmond unit into the disc brake rear from a n 82' Recaro T/A and then I had the 383 solid cam motor built up and then I burned out the 700 and put a TH350 with shift kit and made the AC condensor into a trans cooler. It needed overdrive cuz it was roaring about 3000 rpm at 60 on the road.
My first car was an ‘85 Monte Carlo SS and it had the 305. It was a cool car no doubt but I got tired of getting walked by every Fox Body Stang in the early 90’s and ended up owning 3 pony cars in the following years in my 20’s. I had an ‘85 GT Mustang with a lot of parts in it that thing was a blast to drive
Yep I still have my '85 GT Foxbody and back then I'd walk Monte Carslos and IROC Zs all the time. Even the 5.7L IROCs. (They couldn't breathe above 4,500 rpm with the restrictive 305 tuned port set-up.) 350 is what should've been under the Monte Carlo's hood.
I'm a fox body guy,still have one. But....my buddy had an 88 Monte SS and put a nice spicy little cammed, high compression 350 in it that could run 12s back in the late 90s. He dropped many challengers including my fox, but now mine runs that and his is long gone stolen and stripped
@@danfriesen4417looking back, I’m loving both cars. I currently have neither. However, it would be cool to get an 80’s Monte and throw in a modern LS platform drivetrain and suspension.
@@Turbo4Joe363The 350s of that era were quicker than the Foxbody 5.0s. My buddy had an ‘88 IROC and he never lost to a 5.0. Only an LX 5.0 with a cam and shift kit beat him. It wasn’t stock, tho.
A few years ago I swapped 3.08’s to 3.73’s in my 3rd Gen, and had about the same experience. With mine, it just ran out of breath quicker. Lol Cool side by side test though, especially with the honest results
Also if you’re using the tpi injection setup that has to be accounted for too. They love 3.42s and don’t breathe past 4500 rpm. Treat them like a big block buick not a small block Chevy with those long ports.
Nice video. Thank you for bringing up the torque converter, that is significant, as well as the cam, suspension, afr, tires and pressure and track surface. Gearing is a great start. I am running 4.10 gears with a 27.1" tire behind my torqueflite 727 and a 4000 stall converter and lunati voodoo solid flat tappet cam. Don't know my 1/4 mile times yet, but I'm shooting for low 11's with my small block Chrysler LA360. For now, a set of super stock leaf springs with sliders, no cal tracks. Retaining the torsion bar suspension up front to keep the center of gravity low and towards the rear, I will be dropping down in spring rate for better weight transfer.
I had a 90 Formula 5.0 TPI automatic. Bought brand new. Had 3.08s but never changed them. I put a Paxton Supercharger and cut my et from 15.5 to 14.2. Great cars! Thanks for sharing 👍
Nice job. I went the other way. On a 400, I went from 3.08 to 2.73 in order to improve highway performance and gas mileage. I also put in a T10 with 3.44 first compared to 2.42 in order to compensate.
For people interested in the basic physics of swapping differentials, The higher the number in a differential Goods: = -Quicker out of the hole/off the line -In the hp rpm peak range more -If synced correctly, will almost redline at top end trap (whether 1/4, 1/8, or desired length to top end and top gear) -Better towing uphill, etc. -Quicker ET/MPH in racing -Better racing launch Bads: -More fuel consumption -Higher RPMs throughout driving -Possibly more engine wear (higher RPMs) -Seems like "no Overdrive" -Higher RPMs highway driving Not a drastic swap on this vid. Try swapping a 3:08 to a 5:XX, this will make racing much better, but make OD and general driving much worse/super high rpms Thanks for sharing
I had an 89 Mustang GT convertible that was 100% stock and I ran every week at the drag strip. It ran 9.84 in the eighth mile with the 2.72 gears and an automatic. I changed to 4.10 gears and nothing else and I ran consistent 9.34, so it cut off exactly 1/2 second in the eighth. Really felt it in the seat of the pants.
We had one of those and no dis respect they were slow as all get out . We had a stock one as well as an ASC McClaren Version ( used / bought money from insurance / theft of GT) 89 that got soo much attention it was crazy . Never owned any VERY SPECIAL car , the ASC wasnt a particulary special or expensive car but was different anyway and always got attention ( my Mom would always get startled by Men in parking lots) ,, not even sure beyond body treatment and mercedes comvertible top , leather seats and wheels one single difference but both car people as well as muggles would always ask questions or comment nicely . We had an 88 Manual GT as well . Incredibly different cars in feel. I was unaware the gears were 2.72 ( or forgot after 34 years and I feel like my car had 3.08s) but that seems right it was a bit doggy , a friend had a high mileage,cheap, 84 . first year C4 with the left over engine that was like 200 HP and an auto and I thought it would be a good race and I would win . From a dig I got wrecked . I could see how 4.10s would wake it up considerbly , i think i was unaware and didnt think the auto would lose as much compared to my car. I also tried to test out the top speed and got the speedo into 135 region ( last 10 mph took a while) to where it hit top speed and I ran out of road with sharp turn coming (knew the road but the fast forward and holding out, I over shot my estimate ) and had to panic brake and destroyed the brakes , it was my Moms car ( i owned the MT car) and i tried to act like I didnt know why and my Mom went to dealer figuring warranty and they of course said know and she wanted to know why and the man said somebody stood on them at 135 most likely , expensive test . Years later I had her C5 indicated 150 + on same stretch , I was always a good boy to make sure Moms cars worked right , I actually DID have to blow out her cars as she drove like an old lady for some reason , oh yeah thats right , they would blow out black smoke it was a legit neccesity to regularly red line on all her cars a few times every month .
Yes it was slow, but it was deadly consistent. I always cut a good light and it usually ran within one number. I put many cars back on the trailer with that thing. I once ran a car that was exactly four seconds quicker. At the lights he went by doing 40 M.P.H. more than me. I thought I was going to have to hit the brakes and ended up only winning by a few thousands. It would have been quicker with a manual or even a C-4 and a stall, but I just couldn't force myself in making it less consistent.
The MT cars were not , at least with me driving and particularly on the greasy roads then when 1/2 the cars and every harley was pissing some fluid at stoplights . You had a small window to get a holeshot or know how to sacrifice clutch to get away good . The first time I raced a GN i was like I SUCK , I knew i was not gonna win but dam that thing left with no drama as he knew exactly how to utilize that trans while i had less power and struggled . I built a sleeper 79 vette with a 2700 stall and fresh TH and fresh rebuilt somewhat rare 60s LT-1 350. and it was SOO CONSISTENT , in fact so much so that EVERYTIME i raced my buddy in an anniversary TA with the 3.8 T GNX drive train he got me by 1/2 a car to 100 . They were fast cars though an I was in 10k , same outcome with the new at the time 2Jz turbo Supra that was 50k . It was a great sleeper with dull white paint , stock wheels and big old quiet mufflers and NOBODY ever suspected it . Slowest heaviest corvette with stock 0-60 in like 10 sec. Broke many hearts with that car . Cheers !!
You also have to take into consideration the transmission gearing. 4.10's are fine with a late model camaro or trans-am with the 6-speed transmission, but a Mustang GT that has the old Tremec 5 speed would be much better off with 3.55 or 3.73's because the transmissions first gear is so steep.
I realize it was a diff. gear comparison, but I’d like to see the results of manual upshifts at a bit higher RPM’s. The engine seemed to return and linger too long in the lower RPM “bog” zone. That worked for me in a couple mostly stock, lower HP V-8, 80’s / 90’s cars (- another couple of 10ths.)
first and foremost, minimize tire spin to get apples to apples. You can try reducing tire pressure(might do nothing) and could try loading up the converter more(more rpm before letting off the brake) this will actually reduce tire shock, but you will probably want a little more rear tire. Also, consider that with 4.10s you're likely spending more time in higher rpms and if the valvesprings are old and tired, you're not getting the most out of even a stock cam. These would be my immediate, inexpensive and effective plans. Nice car dude 👍
@JustinOhio while i agree it's marginally important in many situations, traction IS an issue here if he's comparing stats/lining up at random red lights. I'm suggesting real effective changes instead of changing the road like you....
@@JustinOhio Torque, gearing, and most importantly not good enough tires will cause traction issues even in a 20 second capable car. If he refreshes the motor and get's proper tires this is an easy mid-high 14 second car.
I've read through a bunch of the snarky comments below. What I would be asking now with this car is what steps do I take now to take advantage of the steeper rear gears to gain the acceleration they should offer? Bench racing it, I would look to work on the shift points to hold both first and second longer. Then look at improving axle tramp to gain some traction. If you have the room, wider rear tires need a look. Over all, an interesting video that helps to show single changes to a car don't necessarily lead to radical improvements in performance. But making the changes one at a time and testing how performance changes is the most logical path to take.
A gear swap is almost always worth around half a second in et. If you had traction of the line your 60ft would be better and I bet you'd sharpen that up by another 2 or 3 tenths
the dragstrip I go to is in Evanston, Wyoming and is called Hypoxia. the elevation there is about 7,000 feet. my wifes 2018 mustang ecoboost ran like a 9.87 in the 1/8th mile. Ford claims it will run something like 13.9 in the 1/4 at sea level. it's interesting to me to see what changes in the vehicle and how that makes the vehicle run.
Its important to match converter stall with your cam profile. Most stock cams or even lt1 cames i stick with 2500 stall which isnt alot but it worked pretty well with my stockish engine's
If you're only running street tires there's no need for that level of burnout. You're just making the tires mushy, not sticky. A quick dry hop to remove rocks is all that's needed. You can also lower the tire pressure a few pounds but not a lot.
lower gears combined with an engine with good top-end (aka a cam) would make a better ET difference. On a stock engine the lower gears are just helping you get out of the low-end power band faster. But I remember going from 2.73 to 3.73 on my otherwise stock 3rd gen and OMG what a difference it made in feel around town. Great vid. :-)
Makes sense to me. With better traction you'd be under 15 pretty easily. The reason it doesn't make more difference in the 1/4 mile is because your engine is running out of steam on the top end, and it runs out of steam faster with the steeper gearing. If it could rev out a little longer and make more power on the top end it would be much more significant.
Actually, he's not running out of steam - he has a 4sp AT - with the 3.08 he finishes the 1/4 mile in 3rd gear and with the 4.10 he finishes in 4th gear. He's just not making a lot of power so drive train mod (# gears, rear gear, shift kit, converter) will not make big improvements. Which means - MORE POWER is next!
@@salninethousand2496 Oh yea, you definitely want to have a complete combo to make the most of every component. I'm in agreement with you. What I meant by running out of steam is he needs more power or the ability to rev higher. It would actually be preferable if he never had to shift into 4th at all. You generally don't want to shift into an overdrive gear in the 1/4.
Nice firebird. You don’t see many of them anymore. I remember gaining 1 second faster in the quarter from changing in my 87 foxbody mustang. I went from 273 gears to 373.
That's about what I expected. People think a gear changes is some huge difference, and it's not that much. But .2 would be significant if you were racing your buddy that was previously close to your time.
@@carportshenanigans5918 Gearing doesn't really change MPH much. MPH is an indication of HP, and MPH will be pretty close regardless of gearing. It can vary a bit if it puts the motor in its power range for longer, but it still won't be much change. Gears just are never going to make like a half second difference. 2-3 tenths is usually about all you're going to get, in exchange for less drivability. You have to decide which on you want. But as I said, 2-3 tenths can be the difference between losing to your buddy by a fender and beating him by a car length, so it CAN be worth it.
The MPH tells the story…see how much it was up at the 1/8th and not so much at the quarter? Shows it was running out of steam. Hence why I said the RIGHT gear can make a huge difference. This was not the right gear change in this case. You stick to sunroofs and I’ll stick to making big gains with gears.
@@carportshenanigans5918 there was a whopping 3/4 of a mile per hour difference at the 8th of a mile. That's nothing. That's a normal variance from run to run, not to mention a different day, PLUS he was using a dragy and not a real timer. It was basically identical. NO difference.
3/4 mph difference at the 1/8th 1 1/2mph at the 1000’ Then less than 1mph difference at the 1/4. The gains going away prove my point that this was too much gear for the current combination. I regularly see gains of .5-.8 ET and 4-8mph trap speed with gear changes alone. Yes trap speed is a function of HP, but picking the right gear that keeps you IN the power can do wonders for both ET and trap speed…that you don’t know that, tells me all I need to know.
Over a decade ago I had a 1990 RS with a 312 TBI, 2,800 stalled 4L60E and 3.23 gears. It ran an 11.83 @ 119.1 in the 1/4 on street tires on a 1.95s 60'. Just a little naturally aspirated 0.040 over 305. I had worked 113 casting ZZ4 heads, a Comp XFI 280, Edelbrock victor manifold with a 454 TBI on top and Hooker 2460 headers. Little 305 made peak power at 6,400 rpm and carried it well to 6,800 rpm where I had the rev limiter set. I also had L30 305 with a 218/218 @ 0.05 Crane flat tappet cam, 1.7 rockers, ported and milled 059 vortecs, GM 330 hp 350 HO Vortec Q-Jet manifold, 850 cfm Q-Jet and long tube headers in my 1980 Corvette. With a 3,000 rpm stalled powerglide and 3.07 gear that car ran a 12.50 @ 112 mph 1/4 mile on a 2.2s 60' on street tires.
I have recently went to too 081 heads ported and have gained a lot I think the tiny 443 lift cam and old 601 heads are the limiting factor plus car weight 3600 with me in it
@@Krikkebobbyracingchannel Mine was 3,450 without a driver, so I feel we are close there. The 081s are not bad heads but then again neither are the 53cc 601s. The 601s can get up to the 230-240 cfm range with porting. Juat the quick easy cleanup I did on a set resulted in 224 cfm. I used the ZZ4 heads because they were like new off a buddies ZZ4 that he put AFR 195s on. The 113s were 58cc and had 1.94/1.50 valves as well as screw-in studs to start with. I took them from ~205 cfm to 250 cfm on the intake and 165ish cfm to nearly 200 cfm on the exhaust, porting them. Then the heads were milled to 54cc. Made for a 10.7:1 312 at the 0.040" over bore, zero decked with flat tops and a 4.100 x 0.038" head gasket. It made 423 hp @ 6,400 rpm and 408 tq @ 4,400 rpm combined with the XFI 280 cam, single plane intake, 660 cfm big block TBI and the Hooker 2460 headers with matching 3" Y-pipe.
@@chrisreynolds6520 I have few more things planned for the engine in the car but I have another roller block with 305 ported vortec heads and a healthy size roller cam going together over the winter. Waste of time and money for the hp but playing around with something everyone else deems junk is worth it. And being that it’s my wife’s first “street car “ it’s right right up her ally for power management and growing with the car. Just figured I’d share the journey with everyone else.
@@Krikkebobbyracingchannel I think the 305 gets the stigma for under performing because people tend to use the stock heads that need port work to flow well and also further cripple them with too small of a camshaft when they could go considerably larger with a looser converter and deeper gear. I am guessing the 0.443 lift cam you mention is the 50 year old 214/224 grind. Not the cam I would run in a 305 for certain. I have found since I ran that XFI 280 that 305s actually tend to run even better with a single pattern grind. With headers, a ~3,000 rpm converter and 4.10 gear I would not hesitate to run a newer grind with around 226-230 @ 0.050 on both intake and exhaust and a 106-108 LSA. It perks the 305s up nicely everywhere. I also really like the Performer RPM intake manifold. It actually outperforms the Performer or ZZ4 manifold people tend to put on the 305 by about 20 hp with no loss in low-speed torque. If my 90 had not been TBI which being airflow challenged works well with a single plane it would have had an RPM and a Q-Jet on it. Might have actually even run a little better with the RPM/QJet than the TBI/Single plane.
@@Krikkebobbyracingchannel I will also add the Vette ran 0.2 quicker with a 1" tall Hamburger tapered cone Q-Jet spacer mounted open side up on the RPM Q-Jet manifold. I was surprised that it made more power mounted upside down from the conventional way of thinking. If you have a dual plane manifold, might be worth adding a tapered spacer upside down on the existing setup if you have the hood clearence. It blew me away that a chunk of aluminum gained power and slashed ET the way it did.
Not really, 85 TPI 305 Iroc's with an automatic ran 14.8 in the mid 90 mph range. The only year that had 3.42's with an automatic. GM pulled them in 86 because it was as fast as the corvette on most days. I had a few 3rd gens. They were pretty quick. Especially with a 5 speed. All had a max speed of 125 mph. The automatic would not go into 4th under full throttle and the 5 speed did not have enough gear in fifth to go any faster. I owned and tested them both back in the day
Very good video man. I have seen people make this type of comparison yet the run was at a different location and a completely different time of the year. One person's lower gear run was in 30 degree weather and the high gears appeared to be in the summer. Your comparison appears to be a real apples to apples run with likely a similar DA and an identical slope being that you did the run at the exact same location. Had the 60ft time been equal, the 4.10s would have ran 15.30s. Thats a significant difference. Everyone thinks gears are going to be magical, thats just not true. Yes you are going to get into the rpm sooner on the launch but you are also going to upshift into 2nd "higher gear" sooner. So again it isn't magic. Thats a solid gain, again great job with the video.
Right on, we'll worth it! The numbers don't capture the 'Fun To Drive' factor. Around town it would feel much better. I guess the wheelspin hurt the 0-60 a little. This sure sets you up for other modifications down the road.
I agree with those who recommend 3.42 gearing, from experience. My 2000 C5 Vette came with optional 3.15 gearing, stock is 2.73 for the automatic. However the 6 manual comes stock with 3.42 gears and being IRS a gearing swap is as easy as changing the diff housing out. In my case the 3.42 really woke it up and seem to be the perfect all around street gear. I also stuffed a 2800 stall converter, very fun off the line.
IRS makes the gear change much harder to accomplish. Have you actually done a gear change in this car? In a Mustang with IRS it is 3 times as long. It is difficult
I've got 2 f250s with 460 motors. One with 3.55s one with 4.10s. They're nearly identical in a 0-60. Only big difference, the one with 4.10s tows significantly better on hills.
I got my last IROC a 1990 to run some 9.80’s in the 1/8th with a LB9/auto/2.73’s. That was in 2005. I just did the basic mods, Holley adjustable fuel pressure regulator, took the upper intake plenum off and ground the egr shrouds off that were behind the throttle body, bypassed the tb coolant lines, put a decent cap and plug wires on it, tb airfoil, and deleted the cat. The ideal combo for a budget TPI car and remain drivable would to do 3.23 gears, delete the smog pump, add some headers, a shift kit, and a tad more converter. That set up should easily holeshot LT1 cars pretty hard. If you want to take it further find a LT1 cam, vortec 305 heads, and a vortec TPI base and that will put you at LT1 power levels with a lot better torque.
Maybe not enough HP and torque to take advantage of the gearing change? Interesting data though. I run 3.08 in m Buick GS 455 and always wondered if I geared up a bit - I think you can feel the difference but it is a combination of factors that equal ET improvements....I myself just enjoy some power cruising on country two lane roads 60 - 85 mph most of the time, and wouldn't dream of gearing past 3.55..would be allot of fun to try it out though!
To get the full advantage you need a motor a makes more steam in upper RPM's and a converter that allows you to flash/launch at a higher RPM too. I actually thought it would have shaved more ET, but a stock 305 can only do so much.
Great video. I figured there would have been much more difference between the two... Many years ago I had a $63 Dodge polara with a 383 and started out with 3.54 gears and then later on switch to 4.30 gears and even though I never did any timed tests like you did my seat of the pants feeling was a tremendous difference...
Let me chime in, on clapped out 80s bmw's, lol. Old 325 from 84 -91 had a plethora of lsd to picl from. Sourcing complete pumpkins used, would range in price to 250-350 bux. They offered 2.79lsd/2.93lsd/3.73lsd/4.10lsd. even had a "viscous" 4.10 offering for the awd variant. I tried them all. I found the 2.79/2.93lsd gears made the best donuts! They also were better performing in foul weather, like snowy hillclimbs. 3.73lsd would get me chirping 3rd gear though. Id never go for 4.10lsd, after all my findings. Let me add, turbo setups thrive with 2.79/2.93lsd too. 👍
My friend found the same. Took his stock Mustang GT and threw in a race C4 and 4:11 gears. The end result was not as good as expected and his fuel mileage was awful and he had to drive around under 50 MPH. We went on a beach trip in that car and it took forever to get there and back.. He went too far. The C4 had lower gears than the AOD I believe. He decided he should have put in 3.73s. In retrospect he should have had the AOD beefed up. There was not that much of an aftermarket for it in the 80s.
This certainly shows most of the process (not the time it took) and the result is a slightly quicker ET, but barely. Adding a bit more power for the engine would make the 3.08 a much better all around gear for driving, economy and performance. Sure, short bursts of straight line acceleration (i.e. dragstrip) would benefit from a gear multiplication of 4.10s, but you'll suffer everywhere else. Add a stroker rotating assembly and slightly better cam and win with 3.08 gears. The real question you should contemplate is "how far am I willing to go to improve drag strip performance?" A higher stall converter will tax the cooling of the trans (and accelerate wear) and engine heat, will decrease life of transmission and noticeably decrease fuel economy. Good luck!
Easy, convert ur AC condensor to a trans cooler and bypass the radiator cooler and the trans will be room temps all day! I like ur stroker idea too, it's a solid cam 383 stroker in my 83' Firebird in that old VHS from 1996
Your 60 foot went up, probably from a little spin. But with an anemic 305 you're not going to see real gains without more power. A 3.42 with small power adder (i.e. a 50 to 100 nitrous hit) will give you huge gains, especially with a bit better traction.
Rear gears all depends on the transmission gear setup/tire & wheel sizes etc. Normally, the higher the number out back gives you higher rpm but limits your top speed capabilities. The acceleration will be quicker. The lower gear out back will give you a lower rpm and a higher speed. but a slower acceleration. It all depends on what you want your car to do & how you use it.
I had a 1993 Mustang GT that I turned into an LX. I thought it had 3:08 gears in it. Went to a shop to have 3:73 gears put in. Guy came out and told me it already had 3:55 gears in it. I couldn’t believe it. The car barely could get out of its own way. He said they usually put 3:73’s in 5-speeds and 4:10’s in automatics. And that’s what mine was. So he put in the 4:10’s. Absolutely the worst thing I did to that car. I could barely drive it. Even in overdrive, it would be taching around 3 grand going around 55-60 mph. I had some highway commutes for work and it was terrible. I traded it for a four wheel drive truck because I bought a house. But if I would have kept it, them 4:10’s would have been out of there.
I had a 91 GT and an 86 TA 305 at the same time. Still have the GT. It had 2.73 from the factory (5 spd) and put 3.55 in it. The 2.73 really blunted the acceleration. If I remember correctly the Ford AOD ate up a lot of power. When I was test driving auto and manuals they were like different cars. The optional 3.08 made a huge difference vs the 2.73. The cars in the mags were never what you found on the lot (granny gears etc). Luckily Mustangs had lots of aftermarket support and responded to mods. The GM F cars, not so much.
4 anything to me is too low if you drive it on the street. Had a 78 Silver Anniversary Vette mild build with a cam, sounded sweet too but 308 gears were only good for 140+mph so went to 373 and they were perfect for a balance between better take-off and taking the interstate.
I had a 3rd gen formula 350 and it came with an option 3.73 rear end. I also had a h.o. Z28 with stock 3.73 rear end. Both cars were quick in there time. But nothing compared to muscle cars of old and what we have now.
While this generation of Firebird was fairly aerodynamic... they weren't balanced well at all, for drag racing. It takes some serious meats and a fair amount of chassis mods to put down more than 300hp in the first 500ft.
Wow, I thought it would make a bigger difference than that on the quarter mile time. Best results on the 0-60, cut off almost half a second. Could run a 150 shot and bring it in past the 60 foot if you don't want to switch out the 305 for something with more cubes.
As power levels increase,these differences are magnified significantly.A 250hp engine in a heavy car just can’t take full advantage of the torque multiplication provided by the gear swap.Just as carb size,intake configuration ,and header type must be optimized for peak engine power,the power characteristics of the engine,type tranny,and dif ratio must be coordinated for best vehicle performance.I’m thinking that 3.73’s would fit this car better.
That's a decent improvement! But if you still wanna get REALLY fast, that old 305 and slushbox 4 speed have to GO! And if you wanna be UNIQUE, well have I got a neat recipe for YOU. LV3 V6 (yes *V6* from 2014+, same stock power as 5.3 from 2007+), some head work, stage 2 shelf cams, 10:1 compression, 6-into-1 1-3/4 to single 3.5" collector header(make sure it's sequentially/radially fired), Whipple 140AX with custom heat exchanger intake, and last but not least; a ZF8HP-70 transmission swap with a Turbolamik TCU. Regear (again, sorry) for 3.23-3.90 gears to keep hwy RPM in the 2000-2500 range for 60-75mph. Trust me, the 8 speeds will more than make up for it, especially the 4.70 first and 3.14 second gear. TBH even just the ZF8 swap would be game changing. As you already know, gear ratios don't play. Now imagine you have twice as many gears keeping you in the correct powerband, with a first gear that's 50% deeper than your current one. With that in mind as well as the Turbolamik controller, you won't NEED a high-stall converter. You also won't need to spend money on shift kits, transbrake kits, bump boxes, shift under power, or launch control as all of that comes built in with the trans, only needing to be activated by the aftermarket TCU. Hell, the ZF8+Turbolamik combo is so awesome that you can even set up a virtual clutch pedal that'll feel like a real manual clutch and you can 3-pedal your car.
I still have the '90 L98 TA i bought new. It came with either a 3.23 or a 3.27 depending on whether you want to believe the RPO code on the console lid or the sticker on the diff. Most likely the sticker on the diff. Never messed with the diff but the Vortech SC1 increased HP by ~40%.
3.23 was a 10 bolt rear, 3.27 was a 9 bolt. Count the diff cover bolts and you will have your answer. The 9 bolt is the stronger rear of the two but harder to get parts for, used in a lot of Australian GM cars.
@@garthokna7089 Thanks. I've got the 9 bolt "Australia" with the 9EQ (3.27) and Limited Slip tags. RPO sticker lists GU5 axle ratio which is 3.23 per the 1990 Firebird factory service manual. I'll take the 9 bolt.
Not much of a difference considering with the loss of Top end with the 4.10's / When I watch you swap the gears you make it look so easy, never did a Gear Swap with all my years ay Super Shops, definitely can build the hell out of a Holley Carb though.. Next video how to remove those Super Hi End Drum Brakes !!! 😄
Cool test. I have an 08 Mustang 4.6 switched from 3.36 (3.31? I forget) to 4.10s had the same result, only picked up a few tenths. 13.4 vs 13.7. Apparently winding out 3rd wasn't that bad, and with a clutch I could "cheat" the launch a bit with the taller gears.
That's because it was fast then. I thought my '73 Nova with a 2bbl on top of it's 350 was fast, too. Pretty sure it would spring to 60 in under 10 seconds and run the quarter in the mid 17's. 😂
In a drag race if you've got enough power, using taller gears reduces or eliminates a shift or shifts that lose ET. That's why top fuel is the most extreme example of this effect
My 88 monte ss ran good for what it was,3.73 and th350 with a b&m holeshot i was running mid 13s also had exhaust non computer qjet and distributor. Not the quickest but for the low buck it did good. Think i spent around a grand to drop almost 2 seconds for a 305 i like em. Nhra stockers are running 10s in the lighter mid 80 camaros
