Specially tuned for torque, the all new HT 383 delivers great truck power in a small block package. With its 3.80" stroke and Vortec cylinder heads the HT 383 makes awesome torque, down low where you need it for towing or four wheeling off road. Peak torque is 415 ft.lbs at 3500 rpm, but the HT 383 makes over 400 ft.lbs. from 2500 to 4000 rpm. Developed as a truck engine, with a truck grind roller cam, heavy duty forged powdered metal connecting rods, forged crankshaft and hypereutectic pistons the HT 383 is designed to be worked. 325 horsepower at 4500 rpm doesn't hurt either. The HT 383 is an ideal replacement for any 1976 and older carbureted truck engines only or off road application. Details: Specially tuned for torque, the all new HT 383 delivers great truck power in a small block package. With its 3.80" stroke and Vortec cylinder heads the HT 383 makes awesome torque, down low where you need it for towing or four wheeling off road. Peak torque is 415 ft.lbs at 3500 rpm, but the HT 383 makes over 400 ft.lbs. from 2500 to 4000 rpm. Developed as a truck engine, with a truck grind roller cam, heavy duty forged powdered metal connecting rods, forged crankshaft and hypereutectic pistons the HT 383 is designed to be worked. 325 horsepower at 4500 rpm doesn't hurt either. The HT 383 is an ideal replacement for any 1976 and older carbureted truck engines only or off road application. HT 383 Truck Technical Information Horsepower 325 @ 4500 RPM Torque 415 @ 3500 RPM Max. Recommended RPM 5000 Compression Ratio 9.1:1 Block 10105123 Four bolt main, cast iron Crankshaft 1248936 Steel Connecting Rods 10108688 PM rods Pistons High silicon aluminum with offset pins Piston Rings 12522848 Camshaft 14097395 Intake Manifold 12496820 Aluminum dual plane with/dual carb pad and EGR Cylinder Heads 12558060 Vortec Intake Valves 10241743 1.94" Exhaust Valves 12550909 1.50" Valve Springs 10212811 Rocker Arms 1.5 stamp steel Valve Lash Zero Spark Plugs R44LTS or Rapidfire #3 Fuel 87 Octane Ignition Timing 32º total @ 4000 RPM with vacuum advance disconnected