Dart 19100136 Pro 1 Aluminum BB Chevy Cylinder Heads Assembled (1 head)

Dart Pro 1 Big Block Cylinder Heads are inspired by Dart's championship winning Pro Stock designs, the Pro 1's race proven features include rolled valve angles, improved spark plug location, extra long intake valves, raised exhaust ports, and fast burn chambers. Yet the Pro 1 can be used with off the shelf pistons, valve train components, and intake manifolds. Dart Pro 1 Big Block Cylinder Heads feature premium alloy cast from virgin 355-T61 aerospace alloy for superior strength and integrity, bolt on compatibility, 2 degree rolled valve angle and standard spacing accommodating all stock accessories, four intake port sizes a 275cc oval port and 310cc, 325cc, and 345cc rectangle ports cover applications from street to competition, heart shaped 121cc chambers improve combustion efficiency, raised spark plug location improves flame travel for a quicker more complete burn producing more power, multi-angle intake seats and radiused exhaust seats dramatically increase airflow, hardened exhaust seats are compatible with unleaded gasoline, exhaust ports raised .300" to improve flow (requires 1" longer head bolts next to exhaust ports), spark plug holes are machined for gasketed 3/4" reach plugs, manganese bronze valve guides extend cylinder head life and reduce stem wear, as-cast heads are bowl blended on a 5-axis CNC machining centers.