This listing is for one (1) set of King HP main bearings for Ford 429-460 big block V-8 engines. P/N MB5650HP. These main bearings are available in STANDARD size. King has developed their Alecular bearing material as an alternative to the traditional tri-metal bearing construction. Alecular is an exclusive alloy of aluminum, tin, and copper on steel backing. King HP-series bearings have a single, deep layer (.012"-.015") of Alecular material that gives King HP-series bearings superior embedability.