Engine Parts
Chevrolet Big Block 6.5L 396 · 7.4L 454
Traction Drive Systems
Air & Fuel Delivery
Procomp Electronics
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 drivability, 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 AsCast 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.
Turnkey Carburetor
Flow Results PCE281.1523
PCE281.1524
These Flow Numbers are CNC ported Intake Valve - 2.250” Exhaust Valve - 1.880”
LIFT
INTAKE
EXHAUST
0.100 70.2 0.200 145.7 0.300 220.4 0.400 280.3 0.500 328.6 0.600 363.4 0.700 389.4 0.800 404.3 0.900 410.1 0.950 411.7
Turnkey EFI
These Flow Numbers are CNC ported Intake Valve - 2.300” Exhaust Valve - 1.880”
LIFT
Intake Port: 363cc Exhaust Port: 155cc Combustion Chamber: 125cc
Turnkey Forced Induction
INTAKE
EXHAUST
0.100 73.7 0.200 156.0 0.300 236.9 0.400 300.0 0.500 348.3 0.600 381.5 0.700 400.8 0.800 409.6 0.900 415.6 0.950 418.7 Intake Port: 363cc Exhaust Port: 155cc Combustion Chamber: 125cc
62.6 123.4 169.0 209.9 245.0 271.1 292.7 310.6 321.1 324.0
62.6 123.4 169.0 209.9 245.0 271.1 292.7 310.6 321.1 324.0
Bare | As-Cast
Crate Motors
Application
Intake Runner Volume (cc)
Combustion Chamber Volume (cc)
Comp. Valve Job
Intake Valve Diameter (in)
Exhaust Valve Diameter (in)
Valve Angle
Cylinder Head Material
SKU
BBC 396
305 cc
119 cc
No
2.250 in.
1.880 in.
24 deg.
Aluminum
PCE281.1489
BBC 454
320 cc
119 cc
No
2.250 in.
1.880 in.
24 deg.
Aluminum
PCE281.1488
Tools, Accessories & more
Bare | Full-CNC Application
Intake Runner Volume (cc)
Combustion Chamber Volume (cc)
Comp. Valve Job
Intake Valve Diameter (in)
Exhaust Valve Diameter (in)
Valve Angle
Cylinder Head Material
SKU
BBC 454
360 cc
125 cc
No
2.250 in.
1.880 in.
24 deg.
Aluminum
PCE281.1511
1.880 in.
24 deg.
Aluminum
BBC 454
64
360 cc
125 cc
Yes
2.250 in. 2.300 in.
PCE281.1523 PCE281.1524