Dart 19100070M Pro 1 Aluminum BB Chevy Marine Coated Cylinder Heads Bare (1 head)

Dart Pro 1 Marine Cylinder Heads are a new highly efficient chamber with improved fuel distribution, spark plugs located as high and as close to the center of the chamber as possible and five-angle intake seats to shear the liquid fuel and air as it enters the chamber are the product of wet flow research. Dart Pro 1 Marine Cylinder Heads also feature Special Hard Chromate surface treatment for corrosion and erosion resistance (also available on aluminum Dart blocks), premium alloy cast from virgin 355-T61 aerospace alloy for superior strength and integrity, super tough Inconel exhaust valves for long life, 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 cruising 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 lead bolts next to exhaust ports), spark plug holed are machined for gasketed 3/4" reach plugs, manganese bonze valve guides extend cylinder head life and reduce stem wear, as-cast heads are bowl blended on 5-axis CNC machining centers.