LQ4 with l92 head how I can increase compression??
I'm looking for 10.5 compression ratio, so what should I do to rich this ratio? replace pistons with stock flat pistons or milled the heads & which head gasket should I use?


LQ9 pistons w/.040 gasket, 70cc chamber should be 10.55cr.
Stock pistons w/.040 gasket and 64cc chamber, 10.56cr. Milled about .035.
Stock LQ4 is 9.4cr according to GM Powertrain. Ask your head porter about the available chamber size.


