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. CNC Port

Emissions 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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