99 Blue Bird

iTrader: (3)

i want to be able to run as much boost as possible with my new motor setup but not sure what cr is best. my motor is a lq4 .30 over(370) with a stock crank, callies forged rods, and diamond -8cc pistons. i will be using the 317 castings since it seems they are good for boost and i have not decided on which head gasket yet. any info on those is appreciated. and i will be using my stock exhaust manifolds and a ls6 manifold. the turbo kit is a sts rear mount. how much boost will i be able to run with this motor? oh and this is a st car in california so thats why i am going with the sts cuz it has a carb legal number. any flaws in the motor please point them out. thanks everyone

omore01

iTrader: (1)

Hey man, I have a similar set-up to yours, 370 LQ4 forged rods but mine is -16cc pistons. I am also using the 317 heads. I went with GM LS9 head gaskets, they are made for boost and serve my application well. I also have a rear mount TC78 turbo kit. I don't see any flaw on your set-up, just use a nice turbo friendly cam and a good valvetrain and you should be good. A word of advice, since you are manual and going with an STS kit, you should take extra consideration into properly sizing your turbo and turbine A/R size. you want a slightly smaller A/R on a manual STS car to avoid lag, an .81 or .96 A/R will do well. You should be able to max out a T60-1 or T67 on your set-up, expect for either of those turbos to be maxed out before 13 psi.

KILLER-LS1

iTrader: (18)

we need to know the pin height on your pistons!

elias_799

iTrader: (8)

i would like to get the CR a little higher to help the rear mount spool

TurboAv

iTrader: (6)

.050 is a good number for compressed thickness on a head gasket to get you close. You also need to know where your pistons sit in relation to the deck. For example, mine are .015 in the hole. Have those heads been milled or are they untouched stockers? Just do a google search for compression calculator and they will pop up.