Engine Cylinder Head - PCE281.1755

All Speedmaster 23deg. Small Block Chevy heads are available with Straight or Angled sparkplugs. Standard valve sizes are 2.020 in. Intake, and 1.600 in. Exhaust, both +.100 in. length. While the 2.02" valves are standard issue, all of our 23deg. aluminum heads can accept a 2.050 in. intake valve with minimal additional work. HEAD GASKETSThe head gasket we recommend for our 23deg. heads used on 327/350/383/400 SBC engines without steam holes is Felpro #1003. On engines using the GM 400 block, or aftermarket blocks with steam holes, use Speedmaster PCE348.1006 or Felpro #1014.INTAKE GASKETSOur heads are manufactured with both the conventional intake manifold bolt pattern, and the Vortec bolt pattern. If you're installing a Vortec manifold, use Felpro #1255 gaskets. If you are using a convential intake manifold, use Speedmaster PCE349.1002 or Felpro #1266 gaskets.PUSH RODSOur aluminum 23deg. heads typically use +.100" (longer than stock) pushrods, Depending on the components used, it is possible that you may need pushrods shorter or longer than that so we recommend that you use an adjustable pushrod to dial in your rocker geometry and order pushrods to match.SPARK PLUGSAll Speedmaster 23deg. SBC heads use standard 14mm.