.020 under size crank shaft connecting rod Bearings without dowel hole and main bearings compatible with Chevrolet 305 ,327 large Journal & 350 cid small block V-8 engines.. HP series bearings are narrowed to accommodate large radius crankshafts. 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. HP-series bearings have a single, deep layer (.012"-.015") of Alecular material that gives HP-series bearings superior embedability. Available in Your choice of under sizes. Click the box of your particular size needed before adding to Cart!.