Head gasket shim.
It is offten nessecary to lower compression ratio on supercharged or turbo engines. Two options possible
1- is to install low compression pistons
2- install a thicker head gasket shim.
Lowered compression permits you to add more boost to your engine with-out the use of race gas, producing more power, without detonating. G-force Division offers several different thickness head gasket shims, of alluminim or copper material to suite your needs. This option is less expensive than changing pistons, easier to do, and ables you to return to stock configuration anytime. Contact us for any specific application.