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 PCE281.1489 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 PCE281.1488 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 PCE281.1511 heads. The added volume of the PCE281.1511 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 PCE281.1523 with their competition valve job fit the bill perfectly.

HEAD GASKETSEmissions Note:

This part is only legal for sale and use on Uncontrolled (Non-Emissions Controlled) Vehicles or on vehicles used solely for the purposes of closed competition racing.

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