I don't already have both... I'm buying a whole engine. Most likely an LY6 bc it's the 58x reluctor which is literally a direct fit.

If it was worth my while I'd swap the heads while the engine is out of the car.

 

You have the 799's..... if you chose to go that route you can buy a 6 liter shortblock.......

 

The short blocks are harder to come by. I'm leaning toward a low mileage bone yard unit that I can scoop up fairly cheap.

 

True. Easy way to save money though. However its not like the resale on the L92's isn't there if you buy a complete one and dump them. Junkyard and cheap is usually not happening lol. At least the iron block ones are common like the LQ4 so the prices aren't astronomical by any stretch.

 

I found one local with less than 80k for $1200. Not bad IMO.

 

IMO you need to get compression up to 11:1 to even equal a LS2

the 5.3 heads would help there, the l92s can be milled, but not even close enuff on those dish pistons that the compression would come close to a LS2.

 

Thats where I disagree... a 5.3 head is not the answer to chase down an LS2 IMO. Can you match an LS2, and even beat one with the right ported heads, absolutely.

Look at this advanced induction listing for example:
Advanced Induction - 218cc GM 5.3L Head Package

They claim 40-55 HP over the as cast 241's on a 5.7. There comes a point where you can only push your compression so high on the available pump gas. I wouldn't want to go all that much higher than the LS2 is stock anyway. If that ported head is worth say 45 over a stock 241, I'd argue that's only a 20 HP gain over an untouched 243.

Given the choice I would want a set of ported 243's for this build or most other 6.0 builds for that matter... but plain and simple that's not happening.

Lastly... the LY6 is rated for 360 HP... not bad considering how limited the stock cam is. Even if the LS6 cam is only worth an additional 25 ponies that bumps it VERY close to the LS2 in the TBSS. Not to mention that this engine is tuned very conservatively being in an HD to run on 87 octane. In marine applications this engine is rated at 385 for what its worth.

I think the ported 5.3's have their place in the world, but I don't think its on a 6.0. If you are building a super snappy 5.7 that you only plan to rev a hair over 6k, then by all means I think it could be the best option out there.

Again its just my opinion... but ive always been down on the 5.3 heads. I never really saw them as a good option. Again, its just my opinion.

 

243's milled with a light diy port gets my vote if you are really trying to keep cost down. But spend the extra money for a different cam than the Ls6 lol

 

the only difference between a Lq4 and a LS2 is compression. 799/243 heads with a flat top piston vs a dished piston and 317 heads.

bump the compression as much as you can, (mill some 799 heads) put a cam in the lq4 and you will make more power than a stock LS2.

it was easy to achieve 11.7:1 out of my LS2 though. good luck getting that much compression out of an lq4.

in an all out N/A attack, the flat top pistons in the LS2 give it an edge....but the dished pistons of the LQ4 make larger cams easier. i had to flycut my pistons to fit the cam i wanted.

 

I'm not even peeling the heads off this thing because I don't want to spend the money on gaskets... that should put the whole 'budget build' thing in prospective.

Its a daily beater... if it makes decent power great! If not... I won't be changing parts to make that power. I still stand by the fact that I think this L96 with a 2004 LS6 cam will make the same peak numbers if not more than a stock LS2. The bottom end will suffer a little, but as I said before it will still be a lot stronger down there than the 5.3 it is replacing.

If I could have gotten my hands on a cam like the GT2-3 or anything else that doesnt have any lope I would have gone that route too, but the LS6 presented itself for a good price first.