These Steel "H" Beam connecting rods are manufactured from 4340 Aircraft Quality forgings to the same exacting standards developed and approved by OEM customers. There is a vast difference in quality between these "H" beam and the "Other" inexpensive H-Beams on the market. Weight matched to +/- 1.5 grams. Perfectly round big and small ends. Bend and twist is tightly controlled. Cap fasteners are 3/8" ARP 2000 for the "H" Beam. Will fit TU custom Wiseco pistons with matching wrist pin size. Fitment will be required for OEM .901" wrist pins.