This listing is for a set of (8) STD Journal Size King Engine Connecting Rod Bearings and a set of Main Bearings compatible replacements for SBC CHEVY 305 327(large Journal) 350 383 Engines with 2.100" OD Journal Size.This set ifs for Crankshafts with Standard Journals .Alecular material is used exclusively by King. It is an alloy of aluminum, tin, copper and several other elements. Because it is an alloy, it maintains its properties throughout its entire depth, delivering consistent and reliable performance. Available in your choice of under sizes! Just click the box of your particular under size needed to order.