Every intake port, every exhaust runner, every valve bowl and every combustion chamber is 100% CNC machined on special dedicated Pro 1 castings. These heads are ideal for high compression, big inch small blocks and a great for supercharged applications.

Features:
- Premium alloy: Dart aluminum heads are cast from virgin 355-T61 aerospace alloy for superior strength and integrity.

- Bolt on compatibility: Standard valve angle and spacing are retained to allow use of off the shelf pistons and valve train components.

- Fully CNC machined 227cc intake ports produce awesome airflow and fuel suspension characteristics.

- 64cc combustion chambers are CNC machined for maximum consistency.

- Hardened exhaust seats are compatible with unleaded gasoline.

- Manganese bronze intake valve guides and phosphorous bronze exhaust valve guides extend cylinder head life.

- Angle plug style for racing headers.

- Spark plug holes are machined for gasketed 3/4" reach plugs.

- All cylinder heads sold individually.