All Speedmaster 23deg. Small Block Chevy heads are available with Straight or Angled sparkplugs. Standard valve sizes are 2.020" Intake, and 1.60" Exhaust, both +.100" length. While the 2.02" valves are standard issue, all of our 23deg. aluminum heads can accept a 2.05" intake valve with minimal additional work. Some of our CNC ported heads (PCE281.1354-1448) are designed around 2.05" Intake valves. Our cast iron heads use 1.94" intake valves, and 1.50" exhaust valves. For those racers looking for a head with 800+hp potential, step up to our new 15deg heads! These heads have room for huge 2.180"-2.200" intake valves. We even have the matching rockers!

Speedmaster CNC ported cylinder heads are machined on dedicated 4-axis and 5-axis CNC machining centers to ensure accuracy and cost effectiveness.

Combustion Chamber, Exhaust and Intake Ports all fully CNC machined for better flow. CNC combustion chambers offer superior control over flame travel and quench area.