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° 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:
- Aluminum
- Cylinder Head Finish:
- Natural
- Combustion Chamber Volume (cc):
- 121cc
- CNC-Machined Combustion Chamber:
- No
- Combustion Chamber Style:
- Heart Shaped
- Intake Runner Volume (cc):
- 325cc
- CNC-Machined Intake Runner:
- No
- Intake Port Shape:
- Rectangular
- Intake Port Location:
- Standard
- Intake Valves Included:
- No
- Intake Valve Diameter (in.):
- 2.250 in.
- Intake Valve Angle:
- 24 Degree
- Exhaust Runner Volume (cc):
- 129cc
- CNC-Machined Exhaust Runner:
- No
- Exhaust Port Shape:
- Oval
- Exhaust Port Location:
- 0.300 in. Raised
- Exhaust Valves Included:
- No
- Exhaust Valve Diameter (in.):
- 1.880 in.
- Exhaust Valve Angle:
- 24 Degree
- Valve Type:
- N/A
- Valve Springs Included:
- No
- Valve Spring Type:
- N/A
- Maximum Valve Lift (in.):
- N/A
- Outside Diameter of Outer Spring (in.):
- N/A
- Damper Spring Included:
- No
- Valve Spring Pressure Closed:
- N/A
- Valve Spring Pressure Open:
- N/A
- Retainers Included:
- No
- Retainer Material:
- N/A
- Locks Included:
- No
- Lock Style:
- N/A
- Valve Stem Seals Included:
- No
- Valve Stem Seal Style:
- N/A
- Rocker Arm Studs Included:
- No
- Rocker Arm Studs Size:
- 7/16
- Rocker Arms Included:
- No
- Rocker Arm Nuts Included:
- No
- Guideplates Included:
- No
- Valve Guides Included:
- Yes
- Intake Valve Guide Material:
- Manganese bronze
- Exhaust Valve Guide Material:
- Manganese Bronze
- Valve Seats Machined:
- Yes
- Valve Seat Machine Style:
- Multi Angeled
- Valve Seat Material:
- Powder Metal
- Spark Plug Style:
- Angled
- Spark Plug Type:
- 14mm Spark Plug, .750 Reach
- Valve Cover Mounting Style:
- Perimeter bolt
- Accessory Bolt Holes Drilled:
- Yes
- Steam Holes Drilled:
- No
- Oiling Style:
- Through pushrod
- Machined for O-Ring:
- No
- Heat Crossover:
- No
- Quantity:
- Sold individually.
- Notes:
- Exhaust flange will accept stock-type gasket.
- Make:
- Chevrolet
- Engine Family:
- Chevy big block Mark IV
- Engine Sizes:
- 6.5L/396-7.4L/454
- Years:
- 1966-1990
