GT40 Head Swap Mustang First Drive 

LOL, you probably will regret it. This year has been crazy and I’m not sure how much attention the mustang will get. But I do have some videos planned for it. Thanks for subbing!

That’s a great improvement. I’m thinking mine is probably close to what yours did. My combo isn’t that much different. Still super curious what it does though. Especially how much the nitrous wakes it up. Thanks for sharing! Good info 👍

My 90 coupe has the same heads, same intake but a Crane cam and made the same power on the dyno.

That's what I'm trying to do right now I already got the gt40 intake installed ima put gt40p heads and hopefully a cam after awile

@@SuperThugnifacent Cool you can see the dyno video on my channel if interested. 👍

What’s gears are in the car?

Thank you very much!

Nice! In my experience the tear down is pretty fun. Clean up and prep is horrible. Assembly is awesome. Best of luck on your build and thanks for the comment 👍

Hell ya man, thanks! These GT40s needed a big overhaul too. I covered all the steps I took in videos on this channel if you’re interested. I love the cobra intakes! You’ll definitely notice a kick once you bolt them on. It’s almost worth bolting those on the E7s then doing the head swap later. That way you can get a sense of the power difference when you put the GT40s on. Thanks for the comment! 🤙🏻

Nice! That's a good setup...basically what I'm running as well minus the porting.

😂🤣😂 it can strike us all

X2 and the Holley and Edelbrock stickers all over.

That sounds about right! I remember taking mine to the strip bone stock and ran a 15... I didn’t realize it was that slow and was pretty disappointed. Boltons came next and it dipped into the high 13s. Then nitrous got it to low 12s with slicks. I don’t know what it will do on this new combo, but I want to find out. Thanks for the comment!

Did you have to change the valve springs?

Hahahaha, hell ya man. Pesos fines are easier to pay than dollar fines.

Interesting! I didn’t have any knowledge about that. Thanks for the info 👍

Hello. Yes, absolutely upgraded the springs. I ordered them with the cam to match my set up. I’m unsure of the lift tolerances for stock springs, but don’t risk it. Makes a huge difference in performance if you run a weak spring relative to your cam.

Haha, true story man! Appreciated 👍

Haha, yep! You nailed it. 3.73. Traction is a constant issue. Although I’m not sure how some of these cars with much higher horsepower and torque are able to do it. 1st gear is useless for me, 2nd is okay. I only use nitrous at the midrange of 2nd or use only in 3rd or 4th. I have Sumitutoyo (sp?) and there’re not good for much. I will switch to a tire like yours, but that 285 number scares me. Do you have any clearance issues? Glad the valve last video helped you! I appreciate the comment. 👍

Hey there. I'm not sure on the cam...I have the cam card somewhere, but I've seemingly misplaced it... I know it was a xtreme energy comp cam on the mid to bigger side. As far as rwhp, I'd guess 280ish and on the small hit of nitrous probably around 340.

Hell ya. That’s a good combo. Should sound sweet! And add a good amount of power. I’m probably going to be getting aluminum heads too this spring. The GT40s definitely helped, but now I’m used to the power and need more....and on it goes.

Dont do a e303 for more power go with a comp cam with 512 lift with gt40 heads

@@theunknownshadow6926 👆yup. That’s my combo

@@FastFixRU-vid im just hoping i got enough clearance for my valves and pistons if not its gonna bend my push rods again. Im not running a gt40 intake its just the stock intake im praying it works.

The difference was more noticeable than I predicted. A much better head up top as you say. Maybe one day you’ll run into the 94 cobra again and can re-aquifer. The 90 lx is a fun car too. Thanks for the comment 🤙

The extra power was worth it! I would've been disappointed if all the work I put into it gave negligible results. I suspected the E7s to be the clog in the system because it was the one remnant of the stock system. I think you'll find that to be true regarding your camshaft should you choose to keep it stock. Especially if you're running a supercharger. A cam upgrade will do wonders for your combination as I'm sure you already know. It's more work however, but if you're doing a head swap already, maybe doing a cam swap isn't as much trouble... but, I don't know how much front disassembly you'd need to do on your truck to swap the cam. I didn't notice any losses with the GT40s. All gains as far as I can tell. It's better off the line, better in midrange, and better up top. It screams now. I'll be on the dyno in the near future and will make a video of the results. With and without N02. I'm sure you'd see big gains with more free flowing heads. If you were running a turbo, I'd say to just increase boost to make up the difference, but superchargers are different. I'm sure the Vortech will appreciate the increased flow. I assume your truck is tuned for your combination...I'm not sure they run without one, but if it's not I'd definitely recommend that step. Bummer about the emissions restrictions! I will be getting this car to the dyno and possibly do an entire build with it in the near future. Thanks for the comment!

@@FastFixRU-vid I'll be waiting for that video. The 96 is the first year of obd2 and also the eec5 computer which is easier to program. It is their last year for that body, but the 5.0 carried over on the explorer for some time after. I do have a tuning solution and did it myself (Core Tuning). I missed out on fuel injected fords back in the 90's so I'm kind of doing my own version of a 4000 lb mustang. Anyhow I did the usual stuff with changing injectors, fitting a bigger MAF (I've done 2 different 80mm ones and now have the 80mm Lightning maf), and have it tuned to run for 20 percent ethanol which is calif 93 octane, basically. Lots of timing for a supercharger and it goes real well (up to 4500 rpm anyhow). It dyno'd at 280rwhp/315tq and was still increasing hp at 5300 rpm, but the factory ignition has its spark blown out so that's as high as I can rev without doing an MSD 6AL. The stock parts are making it run truck-ish with a higher torque than hp, but that's ok if I can get another 40 hp out of it. I think I can with the blower. The numbers seem low, but it is night and day- the truck has a ton of extra power as soon as you touch the accelerator with the centrifugal and small port heads. Since 96 is a weird year, all the smog legal stuff for mustangs stops at 1995. The only aftermarket heads that are legal for 96 trucks and broncos are twisted wedge 170's which I almost bought, but a 2.02 valve is still big for a 302. I know it would be capable of making 500hp, but maybe not with the full exhaust I have to run...so the GT-40's fit the package better and are cheaper (plus no hit to low end power).

Lol @ 4000 lb Mustang! That's awesome. I dream of having an odb2 port... The CPU is jammed in the passenger kick panel and is a major pain to remove. I have to remove it anytime I need to adjust the tune. That's awesome you do your own tuning. I like to do everything myself too, so good on ya for tackling that. So it seems California has better gas and Nebraska has lower emission controls. Best I can do here is 91 octane. We do have E85 and I've been considering making the fuel system compatible with that, but again I'd have tuning issues to contend with... I'm sure the supercharger is night and day. Your power is respectable and I'm sure the GT40s will give you the 40hp you're after. I believe most dyno sessions report 40hp gain with GT40s on non-boost applications. I would think you'd get even more considering the E7s you've got now are pretty restrictive. Yeah, I like the idea of GT40s vs. twisted wedge. So much cheaper and like you said, keeps the low end power. Thanks for the comments. Always good to hear what others are up to.

@@FastFixRU-vid we only have 91 octane which has 10 pct ethanol, so if you mix five gallons of 91 to one gallon of E85 you get E20 which is 93 octane if you blended it with 91. I can't do any higher because i don't have the parameter for target afr in closed loop, but if you don't stray too far from regular gas, the fuel trims can adjust a little bit. I wouldn't run dedicated e85 anyhow...it is easy to find here, but not that easy. The OBS square body trucks have 2 gas tanks with 2 fuel pumps so i run one tank at E20 blended and the other with standard gasoline for just getting places.

GT40 vs GT40p battle has no clear winner. IMO the GT40s are the preferable head because they maintain stock spark plug location and have a larger exhaust valve. They basically flow at the same rate within a few CFM, so there’s really no performance figure that makes one stand out over the other. The GT40p heads seem to be easier to find, so maybe that’s enough to make them preferable to some. Thanks for the comment 👍

P heads aren’t great if your boosted.

Hello. They heads already had an angle job on them, so I didn’t have to do too much. I’d recommend doing that though while you’ve got them at the machine shop. It’s worth in IMO.

I porter my gt40 lower intake to match the heads. It’ll make a significant improvement. There’s lots of material to be taken out and #1,4,5,8 cylinder runners need to be straightened out

@@alanb2845 you must be talking about aluminum heads? Because my understanding, the lower Cobra Intake, is already larger than the GT 4O 3 bars, so, no need to port the lower if using GT40 irons

@@jpp9846 I used an explorer lower which might be different than the Cobra lower. Either way I was able to remove a significant amount of material to match the heads

@@alanb2845 ok, you're talking about the intake. I spoke to a well known machinist in the Foxbody world and he said that the Cobra Intake (I'm not sure on the explorer) out-flows the GT40 heads anyway, so he advised against porting my lower. (TMoss is the machinist). So I'm just going to run it as is and Supercharge it in the future.

Hello. Check the description of this video. It lists the head gasket link. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-SVhUCuCCo0U.html As far as the pushrods go, the stock ones should work. I’m using stock pushrods on my motor.

Nice man! I got my mustang during my senior year. Tons of fun! GT40P heads will definitely give you more power. The advertised gain is about 40hp I believe. With headers and cam expect those numbers to go up. It’s fun to start from scratch and build up your car. Enjoy it 🤙

Fast Fix awesome!! So I just bought a Gt40 intake that has been ported, a set of GT40p heads and I’m getting a Lunati 284/292 cam, what numbers should I expect from this build? I guess just an estimate if possible. Thank you!!

Hell ya, sounds like a fun project. I think 11s are attainable with that combo. I ran 12.4 with a stock cam, heads, and 140k on the motor. I think my current combo is good for high 11s, so I bet yours is too. Or better. You’ve got a 50hp nitrous advantage To answer your question, no I didn’t get the nitrous system going. I think it’s just a stuck solenoid, but I had another kid and to be honest the car isn’t even registered and I haven’t driven it in months. That will change though! Thanks for the comments! Good to read stuff like this 👍

Bet so! Sounds sweet

Yes, I upgraded the springs. They were matched to the cam profile. I have an entire series on the heads. They should appear at the end of this video. Thanks for the comment!

Yes sir! GBR!!!

Hell ya man!

Yep, sure will! I assume you’re talking about the GT40 intake found on explorers, not the cool tubular GT40 intake. But the bolt patters and such remain the same and will bolt up to E7 heads.

Ok so I actually have the tube intake plentum. Idk the lower matches, but after more research I’m going to upgrade the heads at the same time

Christopher Contreras oh nice, you’ve got the coolest looking intake available! It’s pretty good for power too. I don’t blame you for doing the head swap as well. You’re in for some big power gains by changing them both. Best of luck!

Yes , I have a GT40 Intake manifold on my 91 fox and my I have stock heads

Haha, I agree. I mostly said that so I wouldn’t get roasted in the comments. It’s completely functional and necessary, but I feel like it’s a little out of place considering the car isn’t all that fast. The 78’ sounds sick! 👍

Sure thing. Headers are BBK 1 3/4” long tubes

Hello. I’d say it sounds a little different, but it could just be in my head. The wheels are from American Muscle.

Hello. Running an H-Pipe. Had been using the MAC Powerchamber, but upgraded to long tubes which didn’t match. It’s a 2.5 inch exhaust. It will be upgraded when I get done with the stroker motor. Thanks for the question.

Hello. It’s a Comp Cams 35-514-8.

Right, that’s true. I shouldn’t have referred to it as a ricer tach. But, ricers adopted the monster tacks for use in their non-race cars and ruined the image. So, when most people these days see tachs like this, they think it’s a ricer thing albeit they’re completely functional and often necessary. I catch plenty of crap for mine even though it’s a highly accurate instrument to measure one of the most important functions of the engine. My stock tach is garbage and off by a lot in the upper rpm range.

Hello. They are one piece headlights from AmericanMuscle.com Here's a link that's not a scam :) bit.ly/3FFyyzi

Hello. I used a tuned chip from Bama which is a company within American Muscle…I think anyway. Unsure if the 94-95 mustangs have a port to plug in a tuner…kind of thinking they don’t. I think you’ll need to add a chip to the computer as I did

@@FastFixRU-vid thank you, port is fake on 94-95 mustang, obd1 under hood, guess this is my only option, hoping the bama will work, can you link to software and make your own tune? I’m interested big time.

Here’s what I have: www.americanmuscle.com/sct-4-bank-computer-chip.html

Lol, got close! The factory tack hits 7, but it reads fast. I think this engine can withstand 7k revs though. Doesn’t breakup at all. But I’m too scared to break it!

Hello. I have not. Always intended to, but the nitrous system has been hit and miss (mostly miss) and I imagine the car to be making somewhere in the 250whp range NA. That’s probably a conservative guess, but I like to under estimate rather than bolster unknown hp numbers.

Built Ford tough! 😂👍

@@FastFixRU-vidyeah absolutely i guess so then I got a 94 svt cobra fully built up with a 306. With high compression heads ported Thing screams but I never pushed it that hard in the rpm range was to afraid to blow it up I crank it to 6000 tho 😂

Oh and just Watched the beginning of your video and t see were you say the tac is off 🤣🤣🤣

Damn, roasted.

Killer93LX that’s odd. Do you have an aftermarket ignition box installed?

Valve float

A good reason to keep a $20 under the seat.

agreed!

Damn man…. Coming with the truth I see! No, you’re absolutely right, it was more a preventative measure for possible hazing in the comment section. You’reright man, fuck em! 👍👍👍

Update: it’s still slow Future: Stroker. Heads. YSI. Rambling: remains strong Timeline: TBT

😂😂😂 everywhere is Mexico when speed testing! Lol, thanks for the comment