bwarren337

I was looking in to getting ls3 cnc machined heads for my 1999 Z28 and was wondering if they would work with a MS4 cam shaft..Any info would be greatly appreciated

JeeperSC

I dunno, but make sure its a good cam/head combo before you do all that work. My buddy blindly put different combos together on HIS car. I think he enjoyed experimenting and didnt mind the work. I can do LS1 cam/head swaps in my sleep because of that guy. I prefer to reaearch my plans first to make sure it works the first time.

rv93

somebody correct me if im wrong, but i believe ls3 heads are designed for engines with at least 4" bore. i think the stock ls1 has something like 3.85" bore, and the valves will hit the block. you can use up to ls2 heads, but ive always been told that ls3 heads simply wont fit

WhiteHawk

Need a 4" bore to clear those heads.

-Geoff

bwarren337

So the ls3heads would have to be bored. Any body have any info on whether it would be a good combO with an ms4 cam. Also can anyone tell me what the ls2 heads can produce on an ls1 with an ms4 cam.

Chrome383Z

Ditch the LS3 idea, it's not going to work.

A set of ported LS2 (243/799) heads from AI and a MS4 should put you around 450-460rwhp. If you have them cut them down to 59cc, run a thin head gasket, high octane, flycut the pistons, throw a ported fast on it and you could knock on 500rwhp's door with a bang up tune and maybe the addition of 1 7/8 headers instead of 1 3/4.

I prefer the AI heads to even most aftermarket heads.

rod442

no, they are saying that the ls3 heads need a minimum 4.0" cylinder bore (in the block). otherwise they dont fit.

Ls1 blocks are 3.898 and usually only allow a cleanup to around 3.905. A 6.0l or Ls2 block is 4". and an ls3 is 4.06?

bwarren337

Ok so I ditched the ls3 idea. The ported ls2heads sounds better. Do the AI ls 2 heads come already ported and were would be a.good place to get them

Sparkz28ss

Yes...you can

http://www.mastmotorsports.com/2010/...sembled&id=360

I think gm high tech did a write up about the ls3 heads on a 346ci....I will see if I can find a link

rod442

Neat info, thanks for sharing.

bwarren337

cool great info appreciate it

Marc 85Z28

A poor, poor choice. While those will bolt onto the LS1 and physically work, they're a fancy hack job. There are much better options out there, and all are cathedral port.

AL SS590 M6

$2598 a pair.

Sparkz28ss

Explain this to me Marc. Why are the heads a hack job. Yes they are way to big for a 346 with a mild cam. But if some one wanted to build a high rpm NA small ci engine that spun to 9,000 rpm and made power like a dz302 then it would work. Is it the best choice...probably not. Just because you wouldn't do it or think it's a exercise in futility does not mean that someone else can't get it to work and work well.




As far as the cost...... Come on. You got to pay to play.

Marc 85Z28

First, look at the cost. Second, look closer at the cost - particularly all the additional parts necessary to run those heads. Finally, look at the results. NOBODY has had any real success with those heads on a 3.89 bore. They make power on par with ported stock castings.

The whole idea behind running an LS3 head (and their only redeeming value) on anything but an LS3 is the budget performance aspect. Once you have to pay nearly $3500 for a set of heads (price of heads, rocker, and dedicated intake) they aren't budget by any means and they had better perform along the lines of an AFR 210 or TFS 215. THEY DON'T. There's a lot of work in those heads for a substantial cost only to put you in the wrong direction - therefore it's a hack job. ALL the record setting stock bore engines run a cathedral port for a reason