Serious street performance, mild bracket racing, and marine. Over 7,000 RPM, 525+ cubic inches. Can be used on smaller engines with a tight converter.
The PRO1 24?ø 325cc delivers increased airflow at high valve lift for high RPM, big cubic inch engines, and still remains compatible with off the shelf pistons, valve train components, and intake manifolds.
Long wearing Bronze valve guides, screw-in studs, multi-angle intake seats with hardened, radiused exhaust seats are standard. Best of all, our precision cast ports produce outstanding airflow without time consuming porting.
Assemblies include Stainless Steel valves, premium springs, locks, retainers, guide plates and seals.
Heads are sold individually.
Features
- Cylinder Head Style:
- Bare
- Cylinder Head Material:
- Cast aluminum
- Cylinder Head Finish:
- Natural
- CNC-Machined Combustion Chamber:
- No
- Combustion Chamber Volume (cc):
- 121cc
- Combustion Chamber Style:
- Heart
- CNC-Machined Intake Runner:
- No
- Intake Runner Volume (cc):
- 325cc
- Intake Port Shape:
- Rectangular
- Intake Port Location:
- Standard
- Intake Valve Angle:
- 24/4 degree
- CNC-Machined Exhaust Runner:
- No
- Exhaust Runner Volume (cc):
- 129cc
- Exhaust Port Shape:
- Oval
- Exhaust Port Location:
- Raised 0.300 in.
- Exhaust Valve Angle:
- 15/4 degree
- Intake Valves Included:
- No
- Intake Valve Diameter (in.):
- 2.250 in.
- Exhaust Valves Included:
- No
- Exhaust Valve Diameter (in.):
- 1.880 in.
- Valve Type:
- N/A
- Maximum Valve Lift (in.):
- N/A
- Valve Springs Included:
- No
- Valve Spring Type:
- N/A
- Outside Diameter of Outer Spring (in.):
- N/A
- Valve Guides Included:
- Yes
- Valve Guide Material:
- Manganese bronze
- Valve Seats Machined:
- Yes
- Valve Seat Material:
- Powdered metal
- Valve Seat Machine Style:
- 4-angle intake/3-angle exhaust
- Retainers Included:
- No
- Retainer Material:
- N/A
- Valve Stem Seals Included:
- No
- Valve Stem Seal Style:
- N/A
- Locks Included:
- No
- Lock Style:
- N/A
- Camshaft Style:
- N/A
- Spark Plug Style:
- Angled
- Guideplates Included:
- No
- Guideplate Pushrod Size:
- N/A
- Rocker Arm Studs Included:
- No
- Rocker Arm Nut Thread Size:
- N/A
- Accessory Bolt Holes Drilled:
- Yes
- Valve Cover Mounting Style:
- Perimeter bolt
- Heat Crossover:
- No
- Steam Holes Drilled:
- No
- Oiling Style:
- Through pushrod
- Machined for O-Ring:
- No
- Quantity:
- Sold individually.
- Notes:
- Exhaust flange will accept stock-type gasket. Spark Plug Type 14mm Spark Plug, .750 Reach
- Make:
- Chevrolet
- Engine Family:
- Chevy big block Mark IV
- Engine Sizes:
- 6.5L/396-7.4L/454
- Years:
- 1966-1990
