Clevite 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 seating. They are available with various under-sizes, including 0.001 in. of clearance for polished journals.