Chrysler ESP Rods 6.385 RBStroker 413, 426W, 440 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. Small block rods can be used in applications up to 700HP, and Big blocks up to 850HP.