This 1989 Chevrolet Silverado Crew Cab served many years at GM facilities in Michigan, Arizona, and California. It was bound for the junkyard until Chevy Performance engineers decided to save it for testing their ZZ632 crate motor. The dually truck is now powered by a naturally aspirated 632 ci (10.4 L) ZZ632 V8 making 1004 hp (738 kW) and 876 lb-ft (1187 Nm) of torque. The fourth-generation big-block motor uses a cast iron block with a 4.60-inch bore and 4.75-inch stroke. It features forged 4340 steel crank, forged steel H-beam rods, forged aluminum pistons, billet camshaft, and unique RS-X cylinder heads. Behind the monster motor is a 4L85E four-speed automatic transmission and Detroit locking rear differential.
Source: Chevy Performance