JUNKYARD LS POWER-383 vs 6.0L (BIG BORE vs BIG STROKE) 

There are only a handful of 5.3/4.8 blocks that can be bored to 4.0", but they're easy to spot. If you look on the back where "4.8/5.3" is normally cast, some of the early gen3 blocks have "4.8/5.3/6.0" cast into them. You'll probably only find it in '99-'00 model trucks as GM started producing separate 6.0 blocks since it was cheaper than machining a 5.3 block out to 4.0"

Honestly, Thank you Richard for sharing all this invaluable information with us. Knowledge is wealth.

You're doing the Lord's work with these videos 👍🏻 Thank ya sir

Cubic inches always makes a difference. The 6.0 with tiny chamber heads was pushing a full point higher compression than the LS2 with flat tops, and that pushed the power up a lot. 560x1.04, a 4% increase due to compression, takes you to over 580 right there. The AFRs probably flowed better too, making the rest of the difference. The torque curve of the 383 is pretty impressive. The flat top pistons should give that combo close to 11:1, depending on head gasket, chamber size, etc. Previous tests that compared the Comp 459 to the 469 show the extra exhaust duration improving power at the top. Conversely, using the 459 in the 383 may have improved the mid-range torque, because it sure had some. You mentioned “good” heads on the 383 but never identified them, or at least I missed it if you did. If you can afford the several grand for the rotating assembly, that 383 looks really good. Or you can just put the sub-$200 eBay turbo on the $500 junkyard LS (any size) and there you are!

Excellent video as are all your tests Richard, never been a fan of those Flintstone tech, Lemon Scented, boat anchors, but they are certainly popular amongst the bogans. Merry Christmas to your family and the guys at Westech, thanks for making 2020 better.

You rock for giving out all this free info !!

I JUST pulled my 4.8 (2012) for a mild 5.3. I'll be keeping the 127K 4.8 and make a 383!!! THis video was just what i needed!

Loved the John Doc call out. Seems like good fun

Hey buddy I love your content. This your buddy from Bahamas again.i was one of the first owners of a ls engine! I had a Chevy Silverado when they first came out & love that motor! Keep up the great content ❤🇧🇸

That 383 is killer!!! Thats a boatload of power in a middle-of-the-road combination. Cool vid

I’ve always wanted to put a 3.900” stroke in a 6.0L and have a nice balance of bore to stroke ratio with a mild cam and see what kind of numbers itd throw down!

That's cool you can see the difference between each cam. The 6.0 liter cam pulls harder as you build revs all the way to the top of the throttle, which is awesome.

Been waiting for this!! Thxs!!

383 compares closer to an LS3 than a 6.0, they’re just 1/10 of a liter apart.

That's the comparison I been looking for thanks. Unless u get a sweet deal the price of a 6.0 is pretty close to just getting a crank and pistons for a 5.3 and turning it into a 383 with gen 4 rods

So the long stroke motor makes peak TQ before the crossover point and the big bore motor makes peak TQ after the crossover. This is why I think that starting out with a near-giveaway (or really cheap) 4.8 and stroking it to 4" (since you would buy rods and pistons anyway) is much cheaper than buying a 6.0L (and rods/pistons) to start a project with. All that TQ in the RPM range of daily driving and not having to rev it to the moon to get anything out of it makes sense for a Street Car. Like I said in a previous comment, 4.8L + $700 Summit Racing 4" Stroker Crank is cheaper (where I am at) than a 6.0L by itself....especially if you already have a 4.8 or 5.3. All the hype around 6.0L junkyard specials has caused them to dry up as people are hording them now and when they are available, the prices are insane.

"there's no replacement for displacement" - Don Garlits

I think a more accurate and exaggerated sample would have been your 383 cubic inch 5.3 vs a destroked 388 cubic inch ls7. OR a 4.8 crank in the 6.0 block vs a slightly larger stroke 5.3 block! As always love the content!

Thank you for trying to educate the masses. “Trying” 😇

I’ve bored a 99 model 5.3 to a 5.7. And used ls1 flat tops. Runs great.

I've had both, my 382" (about 15 years ago) was - LS6 block, Eagle rotating assembly, AFR 205s @ 58cc and "Mamo-fied", Crane 228/236 .600"ish lift 114 LSA, FAST 90mm ported by Tony Mamo, Meziere EWP, Kooks 1.75-1-1875 step headers, 3" duals with an X, 42lb injectors, 90mm TB, 85mm MAF, stock 411 PCM tuned, stock rockers - it made right at 480 RWHP and 443 RWTQ through a 60E and a 10 bolt in an F body. Currently have an LQ4 in my daily half ton Silverado, it is a balancing act between - more power, and keeping the ability to tow and daily drive it still. (I think it needs boost) I am building a pro tour-ish 68 Chevelle as well - starting with an LQ4 short block... I keep watching your videos and crunching numbers to figure out the rest of that combo - heads/cam/intake manifold. Keep up the great work Mr. Holdener

The 383 is the type of build that wins races, and is more efficient for fuel economy and/or fuel efficiency. Great to see your experiences, Richard!

This guy is great , this is good stuff

Please make a low rpm torque combination video for all the torque junkies, we love you Richard!!! You’re doing hot rod Jesus’s work bud 👌

Hey Richard I liked the video a lot. Try using OBS to film videos in the future, its open source and you wont have that watermark in the corner. I love the content man keep it coming.

Right on time Richard!😼👍

Hi Richard, I really like your work, I look forward to each of your new posts. I have a 6.0 L76 from a 2007 Silverado MAX that I will be swapping into a SWB C10. I want to keep my rotating assembly stock and get around 550 hp. My plan is to keep the truck intake and delete the AFM, while also upgrading the valve springs, pushrods, and cam. I want a nice choppy idle. I’m willing to mill my heads to bump the compression up but I’m not sure how much to take off and still maintain valve to piston clearance. I know that also depends on cam lift so that’s where my question lies. What cam would you recommend, and how much should I mill my heads? The heads are 823 castings. I will also upgrade my throttle body, fuel pump, and injectors and run long tube headers. I will be using a built 4L60E transmission, and 3.73:1 rear end gears. Could you also recommend what stall converter would work well with this combination? There is so much information out there that it becomes overwhelming. That’s why I wanted to ask you about this build. I know that your knowledge is second to none so I wanted to come to you for your recommendation. Thank you Richard, I appreciate your help.

Damn glad these are both LS based. Me sitting here, building up 383 parts for my 1990 350 TBI V8 Surburban. Square body build. 3 years ago, it was quoted as a "pain" to modify my frame a tad, to fit the LS in its bay. Think a pulley arrangement would have also been the ticket. Soooo' .. parts buying 383 I went. Now here I am .. a set of Trick Flow TBI heads away from sending it all to the machine shop & ordering my 700R4 build .. .. .. literally SURROUNDED by LS powered Square bodies. Wondered so many times, the "pain" supposedly needed for a junkyard LS fitment versus my thousands of dollars in parts thus far.

I would like to see the 363 5.3 standard bore 4 inch stroke comparison to stock 6.0

I am thinking about swapping out my tired 5.3l in my 2000 chevy 1500 z71 and putting in a 6.0 long block with a stage bt2 truck cam with 1.78 long tubes bolted to my fully built 4l60e. I have thought about doing a 383 stroker rebuild on that 5.3. The cost between both is almost identical. However, the long block 6.0 3 year unlimited mile warranty.

I had a 6.0 block bored to a 6.2, 4.065 with ls3 top end. In my c10, has about 15k on the motor runs great.

i noticed there was a bigger percent gain in tq(505/543=9.3% gain in tq) then the percent gain in displacement(364/383=4.96% gain in displacement) so some of that extra tq came from something other then displacement. My theory is the longer stroke gives you more mechanical advantage rotating the centerline of the crank. basically a longer lever. let me know what you think.

Awesome video 🔥🔥

A video on underdrive pulleys would be interesting 🤔

Richard great video, would the results be the same on a 5.7 ls1 bored and stroked to 383 with same bolt ons you used?

I've come back to this video a few times. That 383 with a 23x/24x cam making over 600hp and nearly 550tq is a wicked combo. On the flip side, I've seen stroking the 6.0 into a 416 has brought nearly 650hp and 580tq. If you build it to handle high engine speeds ie above 7k, what more do you need in a sub 3500 lbs car. Spray another 150 hp safely and up to 300 wet with good fuel. I want a dry sump motor like this for a 944 time attack/hill climb car.

the 383 for me Mild & wild. I predominantly run on the street so there is that. 500 plus ft lbs is just fun in that mild 383.

I added a 1/4 inch of stroke to a SBC and it picked it up almost a second in the 660 but I may have changed a few other things to

Man I love how you just welcome the haters to battle in the comments so joyfully. You the man Richard!!!

If you are already quite limited by the heads with standard stroke due to small valves and physically no room to enlarge them, is it better to stick to standard stroke rather than increasing the stroke? According to engine sim software I use this seems to be the case, adding more stoke always reduces power even if I increase cam, comp and all the other stuff but leave heads alone.

I built a 5.3-6.0 last year. She still runs awesome today and it has .144 wall thickness at the thinnest area. The engine is a little monster and I’m more or less “partial” to it because I didn’t think it would last or perform and it has done amazing for 17k miles now. It has a sloppy 2 cam and 799 heads & a $64 set of Diamond Pro Ebay pistons (yes $64 for all 8) I did not want to invest any more money than I had to on a motor I wasn’t sure would even work. It makes 363whp on my dynojet 248X with winpep8 fully updated. Tuned on e85 with HP tuners. Now the scary part, I tried it again and almost went through a cylinder wall. Not all blocks are created equal. Sonic check it before and after make sure you start with a good block. I used a lm7 & Lr4. I’m not sure if it makes a difference but the first build (the good one) started life as a 4.8L and the one that was to thin started as a 5.3L If I build another one I will use .030 over LS1 pistons from Diamond Pro to be sure it’s good. I have 8 sets of those Diamond Pro pistons new in box, I will donate a set to you if you would like a set. They are no longer available for that price on eBay. Message me shipping info if you want them. Displacement comes out to 5.8L with the pistons I have. I have the same $64 pistons in a std. bore 5.3l making 544whp with a GT45 on 14lbs.

I'd like to see a video on the vortec 8100 L18, 496 big block, they were used in Silverado , Sierra's and 'vocational media duty GM trucks 01 '07, A company called Raylor makes performance parts for them, I have a pickup truck with one in it, not sure if it would the worst building.

Pretty soon I'll be getting a C5 Z06. I would like to put a stroker kit in my ls6, but I don't know what size would produce the most power for maximum performance.

You should test ported intakes like a tony Mano fast 102 vs a unported fast 102

Can you do a Ls build or tune for best throttle response? The Ls1 in my Ws6 is a great motor and makes outstanding power but even after a mods and an expensive tune 8m not happy with the throttle response. It’s just not “snappy” or crisp. The carbed motor in my Malibu is super crisp and is a joy to drive. Just want to know if that type of throttle response is even possible with this motor.

Id like to watch a comparison on a 383 vs a stroked 6.0L.

Ls6 383 on my c5 Z06. It’s great, light and crazy torque. And now with a procharger...

love this video and all your videos richard! have you tested a 5.3/383 on boost?? would love to see a video on that!

That power curve on the mild 6.0 is legit!

Most relevant content on you tube performance 👏

If you look at it it is Apple to apples your trying to compromise to the same level in other words you're trying to play on the same playing field as close as possible in conclusion you're always right on I remember these tests that we've done are kind of similar and I'm pretty close good job

The 4.8/5.3 blocks can typically be bored out to the LS1/6 size of 3.898”, I think there are a few unicorns that can be bored to the 4” mark. I’ve got a 4.8 block that has been bored to the 3.898 size and haven’t had any heating issues either!

Richard, I'm just thinking out loud but in your experience what makes an engine more efficient? If you wanted something that was good on fuel, would a short stroke engine lose less to frictional loss? When I spin my short block over with a ratchet, amd the pistons are traveling, it takes more effort to turn, than when they are at TDC & BDC.

Maybe I’ll just get a 4” crank for my 6.0. Dilemma solved. LOL.

I’m here for the 383!! The under dog stroker.. The little stroker that could 💪🏽

I would love to see a direct comparison sbc a 4.125 x3.25 vs a 350 with same heads cam.

The 5.3 can be taken to a 6.0 but different year 5.3s have a little more meat than others. They always ran a wall thickness test on them beforehand and after at the machine shop I used to work at to make sure, some where safe and some borderline safe iirc

I suspect even with identical heads, intake, and cam, we would see similar results. Bigger cubes = more power. But bigger bore means more airflow at high RPM, as you've shown in other videos. So the 383 would make more power down low, while the 6.0 would hit similar power at higher RPM with lower torque throughout.

Hey man, can you do some boosted vortech 350 stuff? Maybe an affordable mandatory supporting modifications for boost kind of deal? I have so many friends that drive late 90s chevys with the vortec 350 and because were all young fathers living paycheck to paycheck, hard to do something to see if it works. We dont have access to the engines and components like you do so it would be really really cool to know what setup works. Thanks for all your work man youre a friggin champion.

How much do you need to clearance the block to put the bigger crank in?

How does that effect cylinder bore wear?

Richard what about some 400 Mopar stroker 451 512

Richard, I looking to use 6.0 LS iron block LQ4 with a stage 3 BTR cam. 799 heads? Thoughts? Going into a 70 C10 with an SM465 manual transmission and 12 bolt rear end.

Yeah we need a ported rec port head test, I feel most LS guys are looking at doing that these days. A.I, TSP, Katech, Lingenfelter, LME, Frankenstein, GPI

Have you ever tried blocking the oil drain back hole's in the lifter valley so oil drains at just the ends, thus reducing oil dropping on the crank thus in theory reducing windage and oil drag. Just curious if it would work.

All things being equal a larger bore/shorter stroke (A.K.A. short throw motor) would rev higher and have a flatter torque curve that peaks late. Making the higher stroke motor a better quarter mile engine and the short throw motor better for road racing. This is because having the torque come on late is better when coming out of a corner since you can get back on power sooner and more safely. Also the higher rpm and later peak gives you more grip in the tire in and out of a turn. Meaning torque at high RPM is smoother, more balanced, has less rev snap and is therefore less likely to overpower the available grip of the tire. To where on the drag strip having the torque come on sooner and harder is going to ripple the tire to launch harder, get through the gear faster and allow you to shift sooner. All good things for drag racing. That is why races with turns favor high revving engines with a late torque peak and drag races favor higher absolute torque that peaks sooner with the overall greater mechanical advantage at the crankshaft. Mechanical advantage is also why some strokers are more fuel and power efficient than other motors of the same displacement. The higher surface area of the piston is why some short throw engines are. High stroke with lower bore = Drag engine. Low stroke with high bore = Formula, cart or superbike engine. That is why drag engines shift around 7,000-9,000 RPM and Formula-1 engines can hit 20,000, but are now limited to 15,000 by the rules. Other things like larger valves with shorter lift, lower displacement, self adjusting fuel runners, power scavenging, multiple length runners and variable velocity stacks, bowl pistons, dual plugs, higher tolerances and lighter parts with less reciprocating mass all contribute to the 20,000 RPM of the bygone era of V-10 powered F1 racing, but the main thing is the high bore and short stroke. Because the same is true with high displacement V8 engines used in road, sprint and circuit racing. Low stroke is typically better for multiple turns and high stroke is typically better in one time straight line acceleration situations.

I have a G8 with a cam 6.0. It has a lot of power but the around town manor is rough.

Have done a lsj or lsa ecotec big supercharger or big turbo or compound charging with twin cooler set-up or 2.4 L ecotec with that set-up I don't know if that cheaper block to buy and have you done mine Cooper engine with the supercharger and turbo connected to it sn45 engine pretty cheap I think

Hi Richard, I would be curious about doing the 5.3 stroker with a 4 inch bore and a set of ls3 heads. I think it could make some decent numbers N/A and booster. Perhaps a future video?

Do #706 flow better on a 6.0 vs 5.3 due to the bore size? I took your advise and build a LQ4 with 706 heads and a BTR Stage 2 truck cam.

Good info!

Ohh and I had a 350 small block Chevy with around nine hundred horses we had each hole machined especially tight for just on piston out the set and had the guy mark them so we knew which holes for which pistons with 300horse 327heads that were shaved and ported as much as possible without getting in the water jacket and both intake and exhaust valves were 202 with triple valve springs and a Crower cam that we matched to the stroke of the motor with and a weiend six inch rise dual plane intake that we opened up also with a Holley eight fifty double pumper on it and a morrosso electric water pump the Holley had been jetted out and had a msd super cool that fastened to the cap of the distributor and a set of long tube three inch hooker headers

when you did the speed secrets for comp cams 1 year ago about the 383 5.3ls i was wondering what length rods you used and piston cc. im in the process of building that combination and any help is greatly apreciated

Love the content, but what the hell were you comparing in this video?

I’d be willing to bet that the cam with the shorter exhaust duration 239° versus 247° would make more torque anyways and sooner. combined with larger displacement it’s no surprise the 383 makes more torque.

Dude in Mexico people they bore out 5.3 blocks to 6.0/6.2s all the time and I’ve never seen or heard one to have a crack a sleeve, this is on boost or nitrous motors also.

Less bore and more stroke would mean more compression right?

It would be interesting to make a 383 out of a 6.0L and compare to a sbc 383. I don’t know that anyone makes a crankshaft for the ls with a 3.750” stoke though.

Off topic - Rich can you help me? I have a 65 289 4.030 and I'm rebuilding it using a eagle 302 crank(2M), do I change my Rods from 5.155 to a 5.090? I see that the boss 302 used the 302 crank and 289 rods? more dwell timing? I see the Ford boss 302 pistons but I am not seeing a lot of piston info, so , Question - 302 crank & 302 rods, pistons , or use the 302 crank & 289 rods and Boss pistons? I'm using world jr heads and going with a retrofit roller about .486 to 531 lift 178 or 182 dur. I was looking for running 9.5:1 Hypern. pistons. my car has a TL 4 speed with 3.25 rear gear. Thank you Rich for being a You Tuber and starting this channel with all this great info!!!

great video.

Ive always been curious, do the light weight internals actually affect power output? Ive seen light weight cranks and even claims that titanium valves and springs would give you more power, ever tested it?

@richardholdener did you have to do any clearancing on the 5.3 for the 4 inch stroke crankshaft ?

Oh Thank you so much Mr Richard I asked for this comp and you delivered I know you didn't do it for me only but sweet otherwise. Intention: 05 tahoe 410 gear 6l80 and they just got whooped buy a woman in a 5.3 lm7 with cam and heads but they dont know its stroked oh so fun fun fun!!!

How bout a 5.3 comparison to a 6.0 with a 4.8 crank?

Richard, I have an idea for a video: Put the same cam in different displacement motor. Say get a 240-ish cam and put it in a 4.8, 5.3, 6.0 and 6.2 with all the same peripherals to see how the power curve is affected.

Great vid. Do you know if a 1.8 rocker can be safely used on this setup and if its even worth it?

what about a 4" stroker on a aluminum 5.3 with a .030 bore you would have a 6.0 liter aluminum block with thicker sleeves for more turbo pressure

So, in identical chassis with identical wheels and tires and identical gearing, how long does the straight have to be for the 6.0 to catch up to the 383?

Hey mate I've buyed a LS1 stroked to a 383 with forged pistons and rods I've had alot of people tell me to run different oils I'm currently running a 20 50 high in zinc oil and it doesn't like it I've read Castrol eage 10 60 oil is the go I'm still not sure what oil I should run as I don't know much on the engine build

I'm building an all forged 383 with twin turbos. And quite frankly. I wish I had started with a 6.0 to get more displacement in the long run. But as it sits. This thing will hit 4 digits easy. So. I guess it is what It is. Everybody wants 1000 hp until they actually drive 1000 hp and realize it's downright scary.

What about a 6.2 v 383 all the same cam ,heads, intake

I've really been going back and forth deciding whether I should stroke my LS1 or get a LY6 block and build it. LY6 makes so much more sense even though it initially costs more. Sell the LS1 and then the LY6 build would almost cost the same if I stroked the LS1.

Thumper cams are they any good in a 6.0 my dad has one in his blueprint 6.0 with CMB CNC LS1 heads and a sheet metal intake

I'd like to see some efficiency comparisons. BSFC numbers.

This is the question everyone ask at some time in their life.

Another great test would be a gen 1 383 vs an Ls based 383! Keeping all things as equal as possible.

Please could we see the chart from let’s say 1000 rpm and up. Some of us would like to know the torque numbers off idle even.

So Richard on the wild 383 motor roughly where do you think the compression ratio was? Great information Great videos

I’d like to see the 4” bore 5.3. Also like to see a 5.3 stock bore with a 4” crank

I have pieces of 2 different engines. I have a .020 5.3l and a crank from a 6.2l. Roughly the same year. Would there be any benefits from running that crankshaft in the 5.3l?