TorqStorm Pontiac 326-455 V8 - Sepentine Supercharger System

9.3:1 max with cast iron. 9.8:1 max with aluminum. Also recommend forged pistons. Not for use with a motor vehicle pollution control device or system. Intercooling is suggested on all non-carbureted applications. A bung is included for water meth injection. Blow-thru carburetor required For Pump gas 93 octane we suggest a compression ratio of 8.75-9.5:1 on aluminum heads depending on pulley size and boost level. If you currently have a pump gas compression of 10:1, you may be able to achieve this compression ratio simply by changing to a thicker Cometic head gasket that we offer.