ALUM 275 2.190/1.880

Dart Pro 1 Big Block Cylinder Heads are inspired by Dart's championship-winning Pro Stock designs. They feature rolled valve angles, improved spark plug location, extra-long intake valves, raised exhaust ports, and fast-burn chambers. Compatible with off-the-shelf pistons, valve train components, and intake manifolds. Made from premium 355-T61 aerospace alloy for strength and integrity, with bolt-on compatibility. Features a 2-degree rolled valve angle and standard spacing for all stock accessories. Available in four intake port sizes: 275cc oval port and 310cc, 325cc, and 345cc rectangle ports. Heart-shaped 121cc chambers improve combustion efficiency, and a raised spark plug location enhances flame travel. Multi-angle intake seats and radiused exhaust seats increase airflow. Hardened exhaust seats are compatible with unleaded gasoline. Exhaust ports are raised .300" (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 center.