I am going to be doing a head swap on my lq4 and im trying to decide wich gasket to run. I will be installing a set of 243 heads milled .020. From my research that should put me around 10.5 to 1 so should i just run a stock replacement gasket or a .040 thick gasket? And if i ran the thinner gasket what would my compression be? This is a stock bottom end lq4. Thanks

 

You'd probably be around 10.7:1 with the .040.

What are your goals with the motor?

 

Its in a 88 trans am with a fast 90 combo th350 with 3600 stall 390 gears 1 3/4 headers true duels. Its a street strip car looking to get as close to 10s on motor.

 

Never use a head gasket to adjust compression ratio. The head gasket sets quench, which will determine how efficiently your motor runs. Use the gasket that gives you a 0.035-0.040" quench. That will make more power, and help prevent detonation at higher compression levels.

 

agree with top post