These steel H-beam connecting rods from Manley are made from forged 4340 steel alloy. They’re packed full of performance features, such as a compact uniform-grain structure for ultimate strength, full machining, stress relieving, and magnafluxing. The wrist pin and big end bores are honed to a +/-.0002 in. tolerance and the wrist pins get a bronze alloy bushing. They include cap screw ARP 2000 rod bolts and each rod set is weight-matched to within 2 grams.