Clevite CB663HN H Series Connecting Rod Bearing Set for GM Chevrolet Small Block and LS Engines 4.8L 5.3L 5.7L 6.0L 6.2LClevite H Series rod bearings were primarily developed for NASCAR racing, but are well suited to other types of competition engines. They're especially good for engines that run at medium to high revs. They have hardened steel backings with thin overlays and a high crush factor, plus a medium level of eccentricity. H Series bearings have enlarged chamfers at the sides for greater crank fillet clearance and are made without flash plating for better