Pontiac GTO 2004-2006 - L92 heads

Is anyone on here rocking the l92/ls3 topend swap with a stock cam?

I have the topend, but with a cam.

what kind of power you making ? around 450 wheel?

Yep - 451 last time it was dynoed.

i was thinking about this exact setup recently- stock cam with ls3 heads. i didnt come up with much after some research. i wonder how it would do?

I would think that instead of buying L92 heads and using a stock cam, you would make more power with a cam and stock 243 heads.

I ran 11.90 with stock heads and a 224/228 cam.

I swapped to the L92 heads and intake and went 11.82............Awesome.

My dyno numbers did go up, IMO the problem with these heads is they are touchy as hell, just no telling how its going to run. It's like you just bolt them on, pick a cam with a blindfold and a donkey tail and see what you get.

A few guys over on ls1gto did the ls3 topend with stock cam. I believe they made around 390-400 rwhp with similar rwtq

A few guys over on ls1gto did the ls3 topend with stock cam. I believe they made around 390-400 rwhp with similar rwtq

You can make that without the L92 heads on the stock cam. I don't think L92 heads are really going to do anything for the OP unless you have a big cam to rev high and use all of that port volume. Even then, I'd rather have a ported 243 head instead.

Stock LS2 heads and cam + bolt ons through 3.91 gears and stock clutch
http://farm9.staticflickr.com/8284/7679148592_9ab3d5a10b_b.jpg

Have you even looked at ls1gto power listings for the l92 swap? Stock cam with l92 swap 415/407. Why wouldn't you do the swap? with the best putting out 486/435.

http://i1191.photobucket.com/albums/z468/NW05gtoWA/12345.jpg

bottom of post #8
http://www.ls1gto.com/forums/showthread.php?t=286447

Dyno numbers just don't tell the whole story, that list you cited is VERY old.

Take what a stock LS3 puts down and consider that it is going to have more cubes, more cam, and bigger MAF than the LS2 swap. Also it isn't going to have valve shrouding like the 4" bore does.

You can count on one hand how many guys have surpassed 11.50-11.60 at the track with that swap, like I said these heads seem to be touchy and unpredictable.

I am not a fan of square port heads

I'll stick to unported 243s before I put L92 or LS3 heads on my car.

471/434 on untouched 243 heads
http://ls1tech.com/forums/multimedia-exchange/1495697-corvette-c6-dyno-vid-ls2.html

Well hopefully I wont be disappointed with my new set up then I'll be pissed if I cant get lower then a 11.50 out of it.

With a good tuner the square ports do just fine

You will do fine with the right cam. I know Arthur J Guy has gone 11.2 with EDC cam/LS3 topend. The guy who I was kind of wanting to follow, has a 227/235 cam and a 3800 stall running 11.3. I like the fact you can get good number's running a smaller cam. I'm not oppossed to ported 243's either. I've actually had LS3 heads and intake, then sold them, thinking I wanted ported 243's. Either way, if you talk to EDC or one of the sponsors, they can get a good cam for you. LS3 swap is not for everyone, the main attraction of it, is you can make good power, at a great cost.

Dyno numbers just don't tell the whole story, that list you cited is VERY old.

Take what a stock LS3 puts down and consider that it is going to have more cubes, more cam, and bigger MAF than the LS2 swap. Also it isn't going to have valve shrouding like the 4" bore does.

You can count on one hand how many guys have surpassed 11.50-11.60 at the track with that swap, like I said these heads seem to be touchy and unpredictable.

I have a crate LS3 with a small cam that first ran 11.4xx and has so far one as low as 11.22 and as quick as 121mph. Square ports seem to work ok:nod:

Ya I just spun a rod bearing so I'm rebuilding the motor, I think I have finally decided that I'm going with 402 stroker, LS3 top end and a Pat G custom cam. I'll just have to wait and see where ill be at.

http://i1191.photobucket.com/albums/z468/NW05gtoWA/2012-08-18_22-23-39_559.jpg

I have a crate LS3 with a small cam that first ran 11.4xx and has so far one as low as 11.22 and as quick as 121mph. Square ports seem to work ok:nod:

You have bigger than 4.000 bore there. No doubt that with the additional cubes and bigger bore of an LS3 they work awesome.

For a budget build they work great, I still think a FAST/ AFR or Trick Flow head setup is going to outrun an LS3 topend pretty bad, of course it will cost more.

We have a guy with a FAST 102 and TFS heads on a stock LS2 short block running like 11.02@123.95 here in California. I don't think you could convince him to use a square port head.

I'm probably not the right guy to ask, like I said I gained 8 hundreths of a second with this swap. To this point it has proven to be a big waste of time.

The cam is just touchy as hell, what works on one car won't work on another, and what one builder tells you won't work, another one swears by.

NW05GtoWA- You might look at a 416 or 418 Stroker, this is the same stroke but on an LS3 bore, probably would work better with the LS3 topend and those big valves.

You have bigger than 4.000 bore there. No doubt that with the additional cubes and bigger bore of an LS3 they work awesome.

For a budget build they work great, I still think a FAST/ AFR or Trick Flow head setup is going to outrun an LS3 topend pretty bad, of course it will cost more.

We have a guy with a FAST 102 and TFS heads on a stock LS2 short block running like 11.02@123.95 here in California. I don't think you could convince him to use a square port head.

I'm probably not the right guy to ask, like I said I gained 8 hundreths of a second with this swap. To this point it has proven to be a big waste of time.

The cam is just touchy as hell, what works on one car won't work on another, and what one builder tells you won't work, another one swears by.


I do tend to agree. The LS3 swap is a good power/great cost swap. The Trickflow or AFR, intake swap, will undoubtedly return a good bit more power. Even the guys I mentioned running low 11's with the LS3 swap, are still in the high teens for trap (I think 119). I think even ported 243's/FAST will yield marginally better results, with DA differences/driver differences, some could argue they are close. Its basically a cost thing. You could have a couple hundred dollars in LS3 heads (after selling your 243's) which is a big advantage, especially for the average guy, hitting the track occasionally.

If I had big money I would have definitely done a bigger cam, fast 102, and tfs heads instead of the ls3 stuff. That said, I have yet to see another auto car at the same track at the same time with those mods run over 1-2 mph faster on the big end than my ls3 junk. Great cost effective upgrade for sure.

You can make that without the L92 heads on the stock cam. I don't think L92 heads are really going to do anything for the OP unless you have a big cam to rev high and use all of that port volume. Even then, I'd rather have a ported 243 head instead.

Stock LS2 heads and cam + bolt ons
http://farm9.staticflickr.com/8284/7679148592_9ab3d5a10b_b.jpg

L92 heads+intake when ported will outflow the shit out of any 243 heads and fast intake.

L92 heads+intake when ported will outflow the shit out of any 243 heads and fast intake.

Thanks, but I'll stick to cathedral ports. :nod:

http://ls1tech.com/forums/generation-iii-internal-engine/1451321-darth-vader-your-lsx-stroker-ready.html

L92 heads+intake when ported will outflow the shit out of any 243 heads and fast intake.

LOL, that's funny.

First of the Cathedral port FAST intake is the undisputed king when it comes to factory style manifolds. While gains with the rectangle port FAST models may be up for debate the cathedral port model is not.

Second there are 6.0 cars toppling 500RWHP with AI ported 243's.

Like many here have said, the LS3 topend is good for a budget build, but in all out trim with a FAST intake the cathedral setup is going to win out, all of this asusming you are on a 4" bore like the OP. Go to a 6.2L and IMO things change.

Just my .02

http://lgmotorsports.com/gallery/albums/userpics/10001/Louis%2008%20vs%20Ants%2006~0.JPG

Despite the extra 14 cubic inches, the LS3 doesn't start making more power until 3.5K rpm.

I think 243 heads on an LS3 block and cam with a FAST102 intake would give much better low end response than LS3 heads with an LS3 FAST102, without sacrifing much in the way of top end.

I would spend the money not on an LS3 topend swap, but on an LS2 FAST102. Obviously, larger displacement motors the LS3 heads will shine, but I would still rather have a set of AFR or TFS than comprable square port heads.

NW05GtoWA- You might look at a 416 or 418 Stroker, this is the same stroke but on an LS3 bore, probably would work better with the LS3 topend and those big valves.

I'm keeping the stock block so I'm just going .005 over I dont have the cash for new ls3. I would like to keep a thick cylinder wall for when I push nitrous.