LS2 or LS3 heads/intake
01-28-2012, 06:32 AM
#1
LS2 or LS3 heads/intake I have a forged 402 LS2 (Callies Compstar crank/rods with Weisco pistons). Currently it has the LG G5X3 cam, traiangle casting 243 heads and a LS1 intake/throttle body. I know the intake is choking the life out of the engine because it is only making 407 rwhp and the torque curve just stops just under 3k.
My question is, would I be better off going with LS2 or LS3 heads with their corresponding FAST 102 intake. I know the stock LS3 heads flow similar to most aftermarket LS2 heads, but I do not know how much less port velocity there is. Basically I need some advice on choosing between aftermarket LS2 heads and CNC ported LS3 heads.
My question is, would I be better off going with LS2 or LS3 heads with their corresponding FAST 102 intake. I know the stock LS3 heads flow similar to most aftermarket LS2 heads, but I do not know how much less port velocity there is. Basically I need some advice on choosing between aftermarket LS2 heads and CNC ported LS3 heads.
01-28-2012, 07:31 AM
#2
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You should be able to pick up a set of used aftermarket cathedral port heads and FAST 92 intake/TB, which should bring it to life. Either way, you'll need a bigger TB to take full advantage of the better flow.
01-28-2012, 02:49 PM
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ls3 heads, stock ls3 intake/ported tb (I suppose you could leave the tb stock too). If cost isn't an issue, Ported ls3 heads, and definitely ported tb. The square port 102 doesn't seem to make more than 12 additional hp on any 402, and that's the best case scenario on aggressive builds. Ported ls3 intakes have mixed results, so I'd simply get a stock ls3 intake and leave it stock.
It should also be noted that for a cathedral port motor above 440rwhp, you essentially need a fast intake. The ls6 piece becomes a significant restriction. Additionally, with a cathedral 402 you need stage 3 ported heads, or risk loss of power. ls3 heads/intake stock seem to do well even on most 416's. Just something to consider if cost is a factor.
It should also be noted that for a cathedral port motor above 440rwhp, you essentially need a fast intake. The ls6 piece becomes a significant restriction. Additionally, with a cathedral 402 you need stage 3 ported heads, or risk loss of power. ls3 heads/intake stock seem to do well even on most 416's. Just something to consider if cost is a factor.
01-28-2012, 04:42 PM
#4
Heres a good idea.
Stock ls3 heads, clean up the exhaust side, hell have a valve job done and defintely mill the heads some to get your compression up.
Stock ls3 intake flows great right from gm. If you have the money to boot for a fast then great but it wont hinder you like the earlier manifolds.
Dont forget these little costs here. You will need a set of rocker stands, and intake rockers as they are offset unlike the previous rockers. A complete manifold with tb/rails/injectors arent a bad idea either and its pretty cheap.
Stock ls3 heads, clean up the exhaust side, hell have a valve job done and defintely mill the heads some to get your compression up.
Stock ls3 intake flows great right from gm. If you have the money to boot for a fast then great but it wont hinder you like the earlier manifolds.
Dont forget these little costs here. You will need a set of rocker stands, and intake rockers as they are offset unlike the previous rockers. A complete manifold with tb/rails/injectors arent a bad idea either and its pretty cheap.
