Improved appearance and design features in almost every area of this casting along with its exceptional price makes this a must when replacing worn out or weak stock casting. Produced from prime C335-T6, a commonly used military alloy known for its stability over multiple heat cycles. Machining is done on state of the art CNC machining centers using hydraulic fixturing for repeatability with strict QS and ISO quality standards enforced. This along with other solid quality features like cast-in high carbon steel inserts, counter bored allen case bolts, large 1/4" NPT drain plug, clearance for up to 5" strokes, and a high volume ported breather make this a professional engine builders choice for your next high performance engine. Fits Harley Davidson 3-1/2" bore Evo engines from 1984 through 1991.