Lightweight 4340 forged steel crankshaft4340 Forged steel H-Beam connecting rods with 3/8? ARP 8740 cap screws or optional ARP 2000 cap screws2618 Forged aluminum Platinum Series pistons with Premium Chrome Moly wrist pinsHigh Performance piston rings & high performance Clevite? ?H? Series rod bearings (narrowed)