Chevrolet SIR Lightweight Rods 6.000 (Bushed) Small Block Chevy 'This all New Design offers strength & Relibility at an afordable Price Forged 5140 Steel Rods ARP Wve Lok Bolts with 12pt nuts (3/8 small Block & 7/16 Big Block) XiRayed , sonic tested & Magnafluxed Shot peened & stress relieved surfaces Good for performance engines up to 500HP