Lsx_Lee6spd

iTrader: (20)

I recently just bought a 99 z28 m6. I owner recently blew the motor and decided to put a rebuilt Lq4 in it which runs extremely strong since i've had it tuned. I know that these are low compression engines ( 9:4:1 ) so I wanna boost the compression ratio up a little, I don't plan on adding any forced induction or anything to it but do plan to cam it soon as possible. So what would be the best stock heads that I could just bolt on and go with ?

garygnu

just mill the heads that are on the engine.mite need shorter push rods.

Lsx_Lee6spd

iTrader: (20)

So just milling the 317's that are on there will boost the compression ?

headed-ws6

iTrader: (34)

Nah look around and get some 243's got mine for 400. add a comestic head gasket aswell. the heads on the car have a 72cc chamber where as the 243 heads have a 65cc chamber. That with a comestic gasket should put you well over 10.1.1 which is what a stock ls1 sits at. oh and the 243's will be worth a good 15-20rwhp with some of that being from the raise in compression. You could also sell the 317 heads on the car for a few bucks aswell.

garygnu

317s have the same port as 243s,just a bigger chamber.it mite be cheaper to mill the 317s then to buy 243s,check for prices with a local shop..do a valve job if you have any valve seat leakage.