The bearings in your engine are a vital component that can make or break your next engine build. That's why we suggest King Engine Bearings. King offers this set of performance main bearings for the B16A, B17A, B18A, B18B, B18C1, B18C5, B20B, B20Z, K20A2, K20A3, K20Z1, K20Z3, K24A1, K24A2, K24A4, and K24A8 engines. The bearings are available in two sizes, STDX (0.005" Thinner) and 0.25mm and are the XP Series, which still uses the tri-metal coating, but are not as robust as the pMaxKote bearings.