HOW TO: LT HEAD SWAP AN LS. GEN V L83 HEAD SWAP ON A GEN 4 5.3L L33. HOW MUCH HP ARE THEY WORTH?

CAN I RUN LT HEAD ON AN LS? WILL LT HEADS FIT ON AN LS? WILL 5.3L L83 HEAD WORK ON A 5.3L LS? HOW MUCH POWER WILL LT HEADS ADD TO AN LS? DO I NEED A CUSTOM CAM TO RUN LT HEADS ON AN LS? WHAT IS THE BEST INTAKE TO RUN ON L83 HEADS? HOW WELL DOES THE L86 INTAKE WORK ON AN L83? WHAT EXHAUST DO I RUN ON THE LT HEAD SWAP? CAN I RUN VVT ON THE LT HEAD SWAP? HOW MUCH POWER IS AN LT HEAD SWAP WORTH? CHECK OUT THIS VIDEO WERE THE GUYS FROM BRIAN TOOLEY RACING SWAPPED ON A SET OF STOCK L83 (LT-BASED) HEADS ONTO A GEN 4 5.3L LS. CHECK OUT THE POWER GAINS OFFERED BY THE LT HEADS, CUSTOM CAM AND L86 INTAKE ON THE LS. ALSO TESTED AN INTAKE UPGRADE, COMPARING THE L86 INTAKE TO THE BTR LONG RUNNER TRINITY!

[@corvettejohn4507]

Would like to have seen a test of the L33 with an LS cam with the same cam specs as the hybrid cam so we can see what difference is caused strictly by the heads.

[@harleyheil]

Agreed. It lost me when the put a cam in the 5.3 that wasn’t close to stock. If that doesn’t exist, a cam of similar specs should’ve been used with the ls heads.

[@filiptrojanek5083]

This test needed to included a cam similar in size to the hybrid cam but tested with the LS heads. I would suspect that only a fraction of the power increase was due to the LT heads especially on a small 5.3L engine.

[@Dane33781]

Different heads can react differently to the same cam. You can't always have an apples to apples comparison.

[@filiptrojanek5083]

@@Dane33781 Certainly. Buy it would give a closer representation of what the heads alone are worth.

[@Fehrway_Engines]

I would like to see the L33 tested with 706 heads, TBSS intake, & a cam with specs as close to the hybrid cam as possible.

[@aaronanderson6892]

Now all it needs is BOOST!!

[@AustinRBa]

I'm curious how this stacks up with just buying some AFR's or other comparable aftermarket heads. Of course those will probably cost more than the LT heads from a junkyard, but having to run special hybrid cams that will limit options. And I'd imagine future availability of these cams will be...questionable. Definitely interesting to see an answer to the question that so many of us have wondered!

[@richardholdener1727]

those questions are why this video exists

[@BLKMGK4]

I'd think buying a full on LT motor of some vintage and going crazy with it might also be a terrific alternative.

[@Turbogto_guy]

So in other words you compared a stock motor to a head swap and cam swap. Pointless test. Literally pointless because you don’t know what the power increase was from just the heads. I guess this is to be expected at this point. Smh.

[@stellingbanjodude]

@@Turbogto_guyyou can’t do the test you described and had you been listening you would understand that. The LT head uses a different valve layout, thus a LS cam will not work. An LT camshaft won’t work either due the the length is longer. It has to be a combination of both, an LS style cam with LT lobe layout. There is only one on the market and commercially available . You guessed it, the BTR camshaft. So no this wasn’t pointless test. The LT heads are way better than most premium ported and polished LS heads, so do some research before you look like a pontificating pretentious person.

[@TurboJohn74]

Thank you Richard for making a good Friday awesome! Great content as always

[@AccuSol-ERN]

I agree with top shelf aftermarket "regular" LS heads being the way to go here. You get the flow you need for big power........without the hassle of keeping track of the hodgepodge of different parts needed. In today's world the aftermarket seems to be pretty quick with offering gearheads the new power parts they desire........you just have to spend the coin. Long gone are the days of garage tinkering to fab up big horsepower parts. Unless you are racing in a class that requires ALL factory parts........I just don't see the point.

[@Macburton96]

I’d like to see an LS3 with LT heads and an lt4 blower and see how it stacks up to modern LT4s

[@derekr1854]

That is some interesting stuff. Wonder what the power out put would be on a 6.0 or even a ls3 motor!

[@Cageisinthebuildin]

Definitely want to see this on a ls3

[@robertwest3093]

I'm blown away by the fact that this engine made 365 hp with a tiny 193@.050 duration camshaft 👍 Another impressive thing is that 389 lb/ft of torque! That's unheard of in a little 323 cubic inch engine!

[@menogusta9829]

It's with headers, tuning and no accessories. He uses an electric water pump and all. Also low coolant temp. So those numbers are inflated from true stock but still good for comparison and maybe a good idea of a bolt on engine

[@carado1984]

Subtract 10% then another 10-15% for drivetrain and your back to 290 wheel.

[@nintendogamer5472]

​@@carado1984the percentage thing is not accurate as drivetrain loss is a fixed amount, say it robs 30hp for drive train loss it would be same loss on a 300hp engine and a 1000hp using a percentage would not be accurate as 10% on the 300hp engine would be 30 but somehow same drivetrain would somehow take 100 HP on the more powerful engine.

[@MichaelJohnson-kg8bk]

Great information as always Richard. Also, the video looks sharp with the green screen or whatever background you are using.

[@Lobo-tommy10]

I can only imagine how much wrenching you actually do for these vids. Thanks!

[@richardholdener1727]

very little for this video-very much for most others

[@realshidd3062]

Big Richard go ahead and slap a LSA blower on it and let’s see what it does for the next video please

[@scotttimpany2845]

ok ok ok.... now I gotta go look for what a 5.3 LS with cam specs similar to the hybrid cam makes for hp. I need to know what percent of increase in attributed to the heads alone!

[@silentbravo]

That custom cam was quite large, 33x / 34x... put a large cam like that in the stock 5.3L and it would bump up a lot in the high RPM range also.

[@timothybayliss6680]

Its almost identical to ported factory castings. Earlier this year Richard published an article building a 5.3 that had Katech 706 heads, LSXR intake, 234/247 625/605 cam and 1 7/8 headers that made 509hp. Those heads were CNC ported with factory valve sizes. The Gen5 heads are probably worth 30-40hp but the CNC program from Katech costs less than the hybrid camshaft.

[@richardholdener1727]

that test is next!

[@MsJohnboy30]

I would love to see this done to the ls1 with ported heads

[@shonuffgl53]

Love your videos, Richard. Guessing someone has already mentioned it... But the l86 manifold picture you used is actually an LT2 manifold. I'm hoping you cover the fuel system on the next video.. guessing the LS3 is coming up.

[@richardholdener1727]

yes, my bad on the photo-the fuel system was a simple port injection. The l86 manifold was modified to accept port injectors, the BTR intake already had them, the DI was plugged in the heads.

[@chrish8270]

Big bang on 6.2 Ls/ lt gen5

[@joshramirez8349]

I love your channel. Have a great weekend Richard

[@kennethpowers8995]

Those LT heads flow great and it’s not all that hard to build a hybrid. If you can snatch up a set of the LT heads for cheap it’s a worthwhile option. Then you just need a cam and a Gen V pattern intake, which you would do a cam and intake anyway even if you went full LS so that’s not extra expense. Aside from that you just need some plugs for the DI ports in the LT heads and you’re basically good to go.

[@richardholdener1727]

custom hybrid cam is much more than LS cam, you also need, rockers, pushrods and exhaust-the hybrid head swap is very expensive

[@kennethpowers8995]

@@richardholdener1727 I forgot about the rockers being different. Headers I wasn’t really thinking about because you would buy a set for whatever setup you’re doing heads on anyway. (Hopefully) Without looking at the flow numbers for Lt heads vs LS heads it really seems like more of a conversation piece at the end of the day then just to say you’ve done it.

[@kennethpowers8995]

BTR makes a decent cam with the swapped lobes for ~$400. I don’t think that’s too bad. Another thing I didn’t consider though is the Right head doesn’t sit flush with the block, meaning you can’t just reuse your LS accessories. That is something I was unaware of too. It seems it’s still a more budget friendly option to just put a nice set of aftermarket or even ported factory LS heads vs doing the hybrid build.

[@Dr_Xyzt]

In my opinion, this isn't a true upgrade if you already have good gen 3 or Gen 4 heads. However, if you have a stock bottom end 6.0 with dished pistons, this would help you get a proper compression increase.

[@myoneblackfriend3151]

I have a Gen 3 6.0 out of a Silverado SS. I have the L83 heads and I am saving up for the rest. Any suggestions for modding the heads?

[@slickcasner4205]

Like to see a LS3 with LT1 heads!

[@Ws6Ms]

Lt1 heads without DI and vvt cam probably won't make any more power over the ls3 head .. but the test would be awesome to see

[@richardholdener1727]

coming

[@shawnlibby675]

Richard holder have you been hearing anything about..l 8 t..6.6.. gas... gen-6 ..I believe.... but with a little bit of work what a crazy engine.. been seeing people work that motor a little bit lately and it's doing good... as a matter of fact 1320 just posted a 91 cyclone still all wheel drive with the l8t 6.6 reassembled with ls heads... and seeing another guy working on in l8t 6.6 gas and he said it's a low compression motor but just removing the cam makes a big difference

[@thomashumphrey5426]

Hell a cam that size alone in the gen 4 would be very close id think

[@butch4481]

Hey Richard when you do cams on the LS motors can you let us hear the camshafts on the video to give us an idea of what they sound like much appreciated

[@Dirtfloorfab]

Hoping to get mine out this year lc9 bottom with l83 heads and a g57 98mm turbo 👍

[@barryhuddlestun3098]

This answers a lot of the decisions about what to do to 5.3. I'll have to save this video. Let it breathe and give it some room for tall stacks. Ad that Hybrid cam and people will be amazed.

[@kennybiggs3944]

It would be great if you can do some more testing on that hybrid that is very interesting

[@richardrohr5106]

Ls7 with ported lt1 heads. Only this time find a way to run both ls7 port injection with the lt4 direct injection. Duel fuel. And then do I need to say it. BOOST!!!!!

[@rustysausage69]

From a builder perspective the hassle of nickel and diming swap stuff to make a hybrid happenmakes me think it would be worth it to run a complete L83 takeout and throw in a cam/tb/intake/DoD delete/with or without DI delete. Prices are coming down significantly on LT engines from a few years ago. That said, pretty cool this can be done. Now what about LS heads on an LT?

[@realshidd3062]

Even for a quick video, I would like to see how the LT two manifold does against the truck manifold

[@BigCapMalp]

We want to see the lt4 super charger with The Lt head + Ls motor

[@DillonAuto]

Nice vacuum plug. I still have the tool in my box, although I'm not sure why.

[@lamboferruccio]

I appreciate that BTR is testing these combinations and developing awesome parts however it is an apples to oranges test, it’s actually impossible to run a proper comparison especially since the intake manifolds are so different oh and the "L86" manifold mentioned is actually an LT2 manifold pictured. A closer test would have been using an actual L83 manifold and creating a custom cam that mimics a stock 5.3 Gen4 truck cam…just saying!

[@speedtweaked2540]

Need another video with the L86 intake and an LT2 intake with the 95mm C7 ZR1 TB.

[@andrewcammer2535]

It's a neat comparison, but there's such a dramatic difference between the two combinations aside from the cylinder heads that it really doesn't tell us much about what we're most interested in, which is how much better are the heads themselves. The biggest question anyone contemplating this type of setup should be why? If the goal is to be different and unique, then maybe it's a good way to go - outside of that there are conventional ways to make that kind of power on that kind of displacement that won't require so many one-off type of parts. Neat to see it done, not real practical to repeat.

[@tedgay8427]

Would be interested to see how they compare to the ported LS7 heads on that 427 used in the other BTR comparison tests.

[@kmack747]

Now to make it an ultimate setup add a set of port injectors and boost

[@joefixxit]

Can you do a 6.0 and 6.2 THEN popular stroker variations. 392,402,408,415, and the big boy. Stroker 427 4.125 boreX4.00 stroke 😊

[@turbosigma]

Yes, needs to be done.

[@richardholdener1727]

LT?

[@joefixxit]

@richardholdener1727 the 427? I had to sleeve an iron lq4 , it was a nitrous motor for about 5 passes and I sent the rear-end and the bed of my truck ahead of the cab lmfao

[@craigchiddo2794]

I want to go the opposite route put ls heads on the lt block and plumb the high pressure injectors into the manifold

[@Fk8td]

475 on 5.3 with a big cam is possible. I don’t think buying all the direct injection parts are worth the squeeze and engine management and fuel system becomes far more expensive. Get a set of upgraded 5.3 heads and big cam and I’ll bet for the same price you can make the same or more without the complications. I personally build direct injection 4cylinder engines and it’s a big limiting factor for fuel and cost is very high.

[@roderickvinson3425]

Also require modifications for head dowels. But available to purchase

[@brianrock3949]

The fuel system was really not diacussed on this deal. BTR is a big proponant of DI, so its hard to brag about big power acheived with port injection.

[@richardholdener1727]

this was port injection on the hybrid motor

[@shaneshane1379]

This test would have been better with a cam closer to stock specs. Maybe a torque RV kind of cam.

[@robertwest3093]

That is one BEAUTIFUL 1970 Chevelle. I had one with almost the same color.

[@BlackyBulger]

Guess I’m rebuilding my Yukon Denali 6.0

[@Qeebss]

I have a gen V 454 outta my G30 I’m trying to get more power and was wondering if you have any recommendations for cams, intake, carb? If anything not much out there I can find and your one of the best in depth engine guy I know.

[@richardholdener1727]

endless choices for that-but the TBI and tuning will be limiting

[@bluecollarhotrods9781]

Part of me really wants to put a set of L86/LT1 heads on one of my spare Gen 3.5 six liters. I feel like it could make close to 600 flywheel without any porting or exotic parts. Not as easily achieved with cathedral port stuff.

[@shadowopsairman1583]

Gen 4 heads will work, no adapters needed lolz

[@bluecollarhotrods9781]

@@shadowopsairman1583 Yeah, but I'm considering a Gen 3.5/Gen 5 hybrid. I'd like a simple, no porting, etc - setup that would make about 600 flywheel. I think someone has a carb intake for the LT heads too. I'm thinking about a suitable engine for my 69 Chevelle. It needs to have a lot of power if I'm not going to put a big block in it. 600ish at the crank would be about right - light, low option car with a 4 speed and 4.10 gears. 👍

[@jesselee128able]

I believe it has to be the L83, LT1 valves are way to big to fit the 3.780 bore

[@shadowopsairman1583]

​@@bluecollarhotrods9781Custom Cam Grind needed is the wildcard

[@bluecollarhotrods9781]

@@jesselee128able If I were putting them on a 5.3L - yes. But the L86/LT1 will fit the 4" bore of an LQ4/LQ9 block.

[@KD0LRG]

Cool video as always but a hard pass unless I come into a lot of extra cash 🍺. I have enough trouble keeping all the gen 3 -4 stuff straight, I made a cheat sheet with all the different blocks and heads for each RPO code.

[@jonstapleton76]

I know the bores would line up, but do the head bolts?

[@jasonhaley5737]

We're doing this to my 6.0 this winter.

[@thetruthspeaker1978]

Now this is and interesting comparison 😊

[@johnbehneman1546]

Great video Richard. Thank you so much

[@scotttimpany2845]

I wonder if BTR would be able to make the runner sections for the "long runner Trinity" out of plastic to cut down on weight

[@StevenAndrews]

Wait? I thought an L33 was gen3 since it is a 24 tooth.

[@tptrsn]

I think they ARE 24x but have Gen4 rods/pistons, so kind of Gen3.5?

[@RageAgaisnt96]

Boost! I love this combination idea

[@thunder57]

What did you do for a fuel system on the L86 intake considering the direct injection is deleted.

[@johnvirgilwilliammccoy2332]

^ THIS! This needs to be answered.

[@Ghosts_and_Cars]

What if you used the direct injection for water

[@claytoncarter]

Agreed.

[@richardholdener1727]

The L86 intake was modified to accept port injectors-DI was plugged

[@raymondkaczmarek5631]

How can you run a stock gen 5 intake on a gen 4 block? I see di rails and valley cover but are they on a gen 4 block or did they modify the gen 5 stuff to take port fuel injection?

[@claytoncarter]

I agree. I doesn’t make sense, but disregard the pictures, they appear to be filler pictures that aren’t accurate. BTR intake is “hybrid” meaning bolts to gen 5 heads but is built for port injection. However, to add to your question, how do you run a plastic gen 5 intake with port injection? It’s not like you can weld injector bosses on it.

[@richardholdener1727]

the DI was plugged, and the BTR intake had provisions for port injection, the l86 intake had likewise been modified to accept injectors

[@tptrsn]

Killer content as usual Richard!! Would it be safe to assume that there is another one coming where you compare the Gen5 hybrid to some other comparable Gen3 or Gen4 setup to illustrate more clearly just how big the difference is? I'm thinking ported 706es with a FAST intake get pretty close to this level of performance for similar or less money?? Or a 6L with stock rec port heads and stock LS3 manifold probably gets pretty close to this combo for less money? (both of these assume appropriate camshaft to make it work)

[@bluecollarhotrods9781]

I'd be really interested in that test... I have an LQ9 going together with PRC Stage 2.5 706/862s, a decent sized cam, FAST LSXRT 102mm, and all the supporting mods. I don't think it will be good for much more than 530ish flywheel. A friend has a 6L with L92 heads, Comp 469 cam, etc. It did 422 RWHP. So, most likely it's in the same range. With porting, flycutting, and more cam it might crack 575-580 on his set up. All bench racing until it hits the dyno cell.

[@richardholdener1727]

yes-coming next

[@tptrsn]

@@richardholdener1727 Excellent!

[@anythingfast4U]

Speaking of the 6.0L, can this head swap be done on the lQ4? Thanks

[@bluecollarhotrods9781]

@@anythingfast4U the LT1 and L86 (6.2L) heads will fit an LQ4.

[@mikew6135]

Hold up! We need the numbers with the exact spec cam on the stock motor or these numbers are worthless. That's a big cam. .644 lift.and plenty of not too much duration. Less duration and a tighter LSA would be preferable

[@scotthultin7769]

Hi RH thank you for sharing 😊

[@420architecMindNDesign]

Now this is cool

[@mky8353]

Boost that combo 👀

[@LS1NNOVATIONS]

Lq with a lt4 blower and heads.

[@button-puncher]

Almost 100HP per liter. Nice.

[@johnbehneman1546]

A Totally Awesome Build

[@bad406camaro]

INTERESTING. i have 3 of these l83 engines sitting in the garage wondering what to do with them.

[@tptrsn]

WHOA! Many good options of things to do with some spare L83s! Lol

[@pitomtlify]

What modifications are done too the LT heads besides plugging the injectors ports? Any machine work needed?

[@corypierce202]

That looks like a LT2 intake instead of a L86.

[@richardholdener1727]

it is

[@shaungiles5986]

HEY RICH, DID YOU HAVE TO MAKE A VACUM LINE BEHING THE L86 INTAKE? AND DID THE HEADS NEED ANY EXTRA WORK BEFORE MOUNTING?

[@AbstractDreamz]

So technically I should be able to swap my L96 6.0 block for a newer L8T 6.6 block in my restomod Regal. .......Or perhaps put an LSA blower on a 6.6 L8T motor and get Big boy power with Big boy torque. This logic should work if you can put LS intakes on the LT blocks, Right?

[@richardholdener1727]

anything can be done

[@WildEngineering]

I feel like your intro is speaking directly to me lmfao

[@bdugle1]

Where’s the comparison to the L33 with a 459 or 469 cam? The 799 heads won’t keep up but how close IS it? A complete comparison probably needs to include another round with cam and milled 799s to make the CR close to even. I seem to recall the 500+ hp 5.3 needed aftermarket heads, and the L83 heads have to be available cheaper than that, and cams should be similar in cost. So what do you get for the cost of L83 heads and L86 intake in a “fair” fight?

[@richardholdener1727]

watch the next video

[@rustygee4919]

What injector setup did you use with the gen v heads and intake on the gen 3 block?

[@richardholdener1727]

both the BTR and L86 had provisions for port injection-the DI was plugged

[@hectorvillarreal3676]

@@richardholdener1727the stock l86 has provisions for port injection? Thank you for all you do for us!!!

[@farncoisbisson7737]

4.8 direct injected!!!!

[@joefixxit]

Give it ALL OF THE BOOST. 😮

[@horsefly1020]

How about LS heads on a gen 5

[@bluegizmo1983]

What about the OG original LT heads, as in the LT1 heads from the 1994-1996 LT1 5.7L? 😂

[@richardholdener1727]

what about them?

[@kylemilligan752]

I'm a great fan of your work Mr Holdener. However, when I mentioned just this same ls/lt hybrid about a year ago on a live feed you dismissed the idea, called it pointless, and basically a waste of time. How would you like your crow served Sir?

[@richardholdener1727]

I still think only handful of people will do this because it's so much more involved than a head swap-watch the next one where I compare it to a mod l33

[@ballingonabudgetlsbuilder5930]

What’s the name of the Cam?

[@vikenlink]

Hi Richard… very interesting installing a LT heads on a LS block. How’s the valve relieve clearance work with different valve configuration, LT cam for sure and the factory extra mechanical fuel pump. That being said, I was wondering, I have the Holley Terminator x max running my LS, I’m swapping injectors from the secret sorcerer to Holley injectors. Do I just scroll to the injectors info on the setup screen and choose the correct injectors or do I have to start from scratch and retune everything?😮

[@richardholdener1727]

this was run with a Haltech, but Holley would also work since the motor ran as a port-injected LS. The DI was plugged and intake intakes had provisions for port injection

[@myblown02svt]

​@richardholdener1727 who modified the l86 manifold for port injection?

[@vikenlink]

@@myblown02svt all you need to do is plug the original injector holes.. tap and thread it.

[@FU2H8R]

Great video

[@68arild]

finally thank you, thank you!

[@78heloman]

The stock direct injection was used ? I didn’t know it could support 500+hp? Anyone know how much it can support?

[@richardholdener1727]

the hybrid was run port injection-not DI

[@stangman962]

What about lt heads with LS7 intake by adaptor plates?

[@anthonyanderson1479]

I wanna see this compared to a similar cam in a l83. why use a gen 3 or 4 short block over the lt?

[@jackdaniels2657]

Why don't we use ls heads on an LT motor?

[@mulletracing8787]

What about l86 heads on a ls2? Wanting to swap my c6 heads for a crazy na set up

[@randy6350]

Wow that’s a lot of lift for a 5.3L. And does it bolt on directly⁉

[@rcguy5793]

Now add boost!!! Please!!

[@Alexwaltman850]

You said the L33 is a gen 4 but I'm certain it's a gen 3. I work at a GM dealership and I know I have an L33 but I also know I have the 24x crank reluctor that came on the gen 3 motor

[@richardholdener1727]

its actually a 3.5

[@joshuajohnson3500]

Im ready to see Lt heads on ls with a 2650 supercharger so i can put that in my vette

[@shaungiles5986]

HEY RICH, CAN YOU DO THIS COMBO ON A 6.0? 🧐🤔

[@russelljackson7034]

Right on

[@RandomHero0637]

I have a gen 3 lq4 6.0 block with 823 heads. Could I swap Gen V lt1 heads on this??

[@richardholdener1727]

IT'S A LOT OF WORK AND EXPENSE

[@joeyjojojr.shabadoo915]

The 'L86' intake you keep showing in the video is an LT2 intake......

[@richardholdener1727]

I know-my bad-they also tested the lS2

[@johnbehneman1546]

Wow I love it

[@bluestangGT2001]

How much of that power gain is due to the cam? Would a similar can profile on the stock LS heads achieve something similar, or would it be a lot less?

[@richardholdener1727]

next test

[@bluestangGT2001]

@@richardholdener1727 looking forward to it!

[@mewrongway]

Anyone know if you can run 2005 Corvette accessories on the 2015 L83?

[@richardholdener1727]

nope

[@mewrongway]

@@richardholdener1727 Thanks Richard

[@Skubasteph]

It’s cool but not worth it at all when there are so many good aftermarket ls heads.

[@johnbehneman1546]

I love hybrid

[@overbuiltautomotive1299]

Richard rocks

[@6oblintv]

This tells me an LS3 hybrid with hi ram or trinity would make 700 easy