Chevrolet ESP H-Beam Rods 6.635 Big Block Chevy The 3-D stroker design offers reduced weight with no sacrifice in strength.Heat treated, stress relieved, certified 4340 steel 2-piece forgings for increased strength. X-rayed, sonic tested, magna-fluxed, all surfaces 100% machined with extremely tight tolerances, bronze bushings for floating pins.ARP 7/16? 8740 cap screw bolts with a stroke design for monster cam clearances. ESP Connecting rods provide the strength and durability required in unlimited engines at a sportsman rod price.ESP rods for Big blocks up to 850HP.