Low-Compression Cam - Big TwinCaracteristicas: Designed with a combination of shorter durations and higher lifts to offer the advantages of a broad torque output through the entire rpm range Designed for hydraulics, but could be run with solids Grind #1 is the low compression version of an "A" grind cam for 74" and 80" models Made in the U. S. A. On late 77 and later engines, the pitch diameter on the camshaft, pinion gear and breather valve gear was changed. These components are