ALUM18BARE CASTING (NO C

Dart 18 Degree Race Series Cylinder Heads feature premium alloy cast from virgin 355-T61 aerospace alloy for superior strength and integrity, compatible with most components designed for 18 degree heads, shallow combustion chamber design improves combustion and allows use of larger valves for improved air flow, interlocking ductile iron valve seats are compatible with stainless steel and titanium valves, valve seats will accommodate up to 2.200" intake valves and 1.625" exhaust valves to maximize flow, valve centerlines with standard 1.935" spacing for optimum valve locations with different bore sizes, spark plugs are shifted toward bore centerline to enhance flame travel and reduce spark plug advance requirement, refined intake port design reduces turbulence and improves air/fuel flow, tall short side radius and deep valve bowl enhance low lift flow, water passages between exhaust ports improve cooling and prevent "hot spots" that can cause head gasket failure, gasketed 3/4" reach spark plugs offer widest selection of heat ranges, integral bosses can be drilled for fuel injection down nozzles.