Clevite MS2199P Main Bearing Set for GM Chevrolet LS Gen III IV 4.8L 5.3L 5.7L 6.0L 6.2L LSMain Bearing, P Series, Standard, GM LS Series Clevite P Series main bearings are the oldest members of the Clevite 77 bearing family and are intended for high revving engines. To compensate for the high load factors and distortion in these engines, these bearings have higher eccentricity and a high crush factor. P Series bearings are constructed of tri metal cast copper lead. They have a steel back for support, a cast copper lead lining to withstand