Gen3 vs Gen4 LSx heads....

[sman]

Thinking of upgrading my stock casting 799's.

Discuss...

[Iroc'nthe87]

to ls3 heads?

[1BADAIR]

Whatcha talking about Willis

[sman]

For a 4in bore, do the square port heads actually get me anything? Would my money be better spent getting mine ported? Or get a set of aftermarket cathedral port castings?

[Gregs_gsxr]

good info and read:

http://www.ls-guy.com/heads/

[1BADAIR]

square port would require intake, rockers, and a diff cam for the best performance

[Gregs_gsxr]

square port would require intake, rockers, and a diff cam for the best performance

money wise, best would be port job on what your have

[farmington]

ls3 heads won't work on a ls1 because the bore is too small. interference with valve and cylinder wall. your best bet is to go with ported cathedral heads. They will make as much power as a Gen 4 head too. Plus no new rockers and intake to buy

[1BADAIR]

He doesnt have an ls1

[sman]

Currently have an LQ9, but considering an aluminum block.... Was just thinking if I am swapping out the short block I might as well do something with my stock casting heads that I'm sure are leaving a lot on the table. I was wondering if its worth it to move to square port heads (considering new intake, rockers, etc) or if I should stay cathedral. Sounds like I can make the same power either way.

So, are aftermarket castings really worth it? Should I just have mine ported and have bigger valve put in?

[Gregs_gsxr]

just depends on how much you want to invest into it thats it.

[sman]

Minimal as possible, but id really like to see better NA numbers this year.

If im building up a different engine id like to see some improvemtn over what I have.

[Iroc'nthe87]

Not sure how cost effective it would be to switch to an alum block, especially when your engine is pretty much identical outside of the block weight. If you were adding additional cubes, it might be a different story.

What is your current set-up now? 799 heads with an ls6 intake and cam? Whats it put down?

[sman]

Well, a member here has offered me a deal I don't think I will be able to refuse on a 6.0 aluminum short block. I will probably do that regardless, just to get 100 extra pounds off the front end of the car. My thought was just putting this together over time and once complete pull my existing 6.0 and swap the all aluminum one in.

Current setup is an LQ9, LS6 intake, Custom Ground EPS cam, Yank SS4000. Last time on the dyno was with a Mike ridings coveter(converter was locked but slipping according to DR phil) it make 390/390 IIRC. Have not had it on the dyno again in the last 2 years since installing a REAL converter. But, no idea how much loss I was seeing with the old one locked, could have been minimal.

[Gregs_gsxr]

need bigger intake and throttle body, going to need to move more air to make more power.