Speedmaster Master Edition One | Page 84

As with all Speedmaster cylinder heads, our Big Block Chevrolet heads are“ Gravity Die Cast”. This casting process creates a much more uniform and robust cylinder head. With the increasingly large displacements becoming common, the need for more airflow is necessary. If you are looking to build a 400-500 + hp engine, give our SM3021-396 heads a try. They offer a smaller cross- section to increase the incoming air’ s velocity, resulting in great driveability, power and economy. On engines over 500hp, use the rectangle port SM3021 heads. The mid-size cross section works well on engines under 540cu. in and under 7000RPM. If you are working on a larger, or higher RPM engine, step up to the CNC ported SM3028 heads. The added volume of the SM3028 intake ports( 360cc) helps to fill in the gap between As-Cast performance heads and All-Out racing heads. If you’ re looking for 750 + hp the SM3028-125XLVJ with their competition valve job fit the bill perfectly.