Ls1manSS

Ok first off I know that these heads are factory casting but I've seen more people lift there heads rather than crack them. My shortblock is a 390 all forged, 9.8:1 cr, e85. I would love to use my heads instead of spending big money on AFR etc, etc.. My question would be if I have my machine shop o-ring, receiver groove and cooper gasket would help this or not??? Or do I just have to suck it up and go aftermarket??? All help and input welcome, thanks to all fellow LS brothers..

Phil99vette

iTrader: (11)

Whats the goal 1400-1800hp?

Ls1manSS

Im shootin for a 1K at the tires. Its going through a 9in and th400 so 1300-1400 flywheel is close to what id need.

Phil99vette

iTrader: (11)

You need a good quality 3/4" thick deck head for that power and it will not need anywhere near 30# of boost to make 1300hp at the flywheel.

Texas_WS6

iTrader: (9)

Here Here. Phill is correct.

Phil99vette

iTrader: (11)

it might be 2 different motors but I made 1200hp to the tires through a glide and a 3.50 9" at 13# of boost. A 390" motor with the right cam,heads,intake would make your power at 16-18# of boost fairly easily.

Fb0dy0nly

iTrader: (10)

I agree with philly here, 30lbs seems like a heck of a lot of boost for just 1kwhp. What are you using to make the boost on that 390?

Ls1manSS

Great help keep it coming. And the reason I say 30lbs is because our snap-on guy at work "was" selling an F2. And I say was because he took my offer on it today!! And now I will be using a 4.0 stroke intead of a 3.8..

Ls1manSS

And I guess I shouldn't hold back at this point about the heads, although that guy in Sweden made 1300 on stock 6.0 heads/crank. I've been told he's made more but I've seen no proof yet.

93formto98T/A

iTrader: (28)

Just to clarify: you're running an auto tranny, 408 ci ls motor, and procharger F2 and want to make 1K rwhp on stock heads? First off an F2 is overkill for 1Khp and you'll lose a lot of power just to turn that big of a blower submaximally not to mention you'll need a cog drive to turn it w/o slip. You'll be closer to 15-17psi at that power level with a more appropriately sized F1a/c/d w/ribbed belt drive. Stock heads will eventually warp/lift even if they hold on the dyno for a few pulls. You paid ~$3K for a used blower and you want to run $150 heads? If you just want "30psi" then run a 1" tube from the intercooler to the TB and whala.

Chris81

iTrader: (1)

He was using pyramid type rings to get it not to lift those stock heads.. he has a neat new head gasket setup now.

He runs an LSX 6 bolt block and Trickflow heads now with those new gaskets and has made over 2000 hp.