This is a Heavy Duty Tri-Metal Main Bearing Set for a Spitfire 1971 to 1980 and MG Midget 1500. These bearings are made from the same material as the Vandervell VP2 bearings, Cu 74.5%,Pb 21%,Sn 4.5% with an overlay of Pb 85%,Sn 12%,Cu 3% on Ni barrier. Please use pull down menu to choose bearing size