ALUM3101212.250/1.8801.55

Dart Pro 1 Marine Cylinder Heads are engineered for optimal performance with highly efficient chambers and improved fuel distribution. Key features include: Spark plugs positioned high and centrally for a quicker, more complete burn. Five-angle intake seats to enhance fuel and air entry. Special hard chromate surface treatment for superior corrosion and erosion resistance. Constructed from virgin 355-T61 aerospace alloy for exceptional strength and integrity. Equipped with super tough Inconel exhaust valves for extended durability. Designed for bolt-on compatibility with a 2-degree rolled valve angle and standard spacing for stock accessories. Available with four intake port sizes: 275cc oval port and 310cc, 325cc, and 345cc rectangle ports, catering to various applications from cruising to competition. Heart-shaped 121cc chambers improve combustion efficiency. Multi-angle intake seats and radiused exhaust seats significantly increase airflow. Hardened exhaust seats are compatible with unleaded gasoline. Exhaust ports are raised 0.300\" to improve flow (requires 1\" longer lead 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 5-axis CNC machining centers.