Speed Pro bearings are built on premium 1020AK steel backings and overlaid with Sealed Power's super-duty H-14 alloy. Then that's covered with a nickel barrier, followed by a thin lead-tin-copper over plate.
Unlike other performance engine bearings, there is no flash tin layer on top of that. Sealed Power's engineers have determined that such a layer can actually move around under high loads--sometimes with undesirable consequences. These bearings have 3/4 oil grooves for enhanced lubrication, while maintaining a maximum bearing surface area.
They also feature Sealed Power's exclusive contoured-flange thrust bearing technology for higher thrust-loading capacity.