Ive got an ls1 with a turbo and im buying a 418 or 427 shortblock and i plan on boosting her up into the 800 hp range. I was wondering if my ls1 heads would bolt on? i think they do not 100 % sure though.
Ive upgraded the springs and retainers already, but would be a big restriction running ls1 heads on that motor? Am i leaving alot of hp on the table?

 

even ported the heads are gonna be a considerable restriction. unported they will be a HUGE restriction.

besides, a 418 or 427 will be a bigger bore, so heads designed for it would be a better option.

might as well go for some ported l92 heads

 

roughly how much are ported l92 heads? and who are some good vendors?

 

texas speed
thunder racing
advanced induction
total engine airflow

not sure who all carries l92s

 

thanks man

 

What block are you running?????

 

i think im going to go with the ls3/l92 418 ci shortblock

 

After a LONG thread on the subject; West Coast Cylinder Heads. Killer CNC'd dyno numbers. Numbers are increased across the board with no torque loss. I'm impressed enough to the point that they are where my LS3 heads are going for porting.

 

i was checking out west coasts web site and it dosent look like they sell LS3 heads or am i missing them?

 

Here is a direct link to their L92 page clicky

 

What is the LS3 casting number?

 

thanks

 

The 2008 Corvette LS3 head casting is known as the "821". It is an investment cast -as opposed to sand cast- unit, if memory serves. I'm not sure if GM stuck with them for the 2009 units or went to something else. They flow killer as cast.
The valves in the L92/LS3 have gotten a LOT of bad press of late. Some say that they are not reliable in performance application being two piece units. I think the LS3 pieces are a bit better than the L92 items. The LS3 units are the sodium filled. If I'm correct the L92 just runs either hollow or solid valves. Still nice if you don't plan on revving the **** out of them. I'm not sure of the credibility of the failure claims. I've run 2 sets of these LS3 heads with excellent results and no valve failure.
I'll have to find it, but WCCH has published flow numbers (in another thread) for thier CNC'd LS3 heads that are easily on par with top shelf C5R heads. It looks like they maintained the flow rate also. This means that they didn't simply open the heads up for maximum volume. Some serious thought went into it to maintain a linear power curve with no dips all the way up to redline. I was VERY impressed. Soon as I can afford it, they will be getting my LS3 heads.