Specially tuned for torque, the all new HT383 delivers great power for trucks and heavy cars 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 425 Ft/Lbs at 3500 RPM, but the HT 383 makes over 400 Ft/Lbs between 2500 and 4000 RPM !
Developed as a high torque engine, with a low end torque 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 should only be used in 1979 and earlier pre-emissions street vehicles or any year off road vehicles.
Power: 340 HP @ 4500 RPM, 435 ft. lbs. of torque @ 4000 RPM
Displacement: 383 CID
Bore x Stroke: 4.00” x 3.80”
Compression Ratio: 9.1:1
Recommended Fuel: 87 Octane
Block: Cast Iron, 1 piece rear seal, 4-bolt main caps
Crankshaft: 4340 Forged Steel
Connecting Rods: HD Powdered Metal Steel
Pistons: Hypereutectic Aluminum
Camshaft: Steel Hydraulic Roller Tappet
Cam Lift: .431” Intake / .451” exhaust
Cam Duration @ .050”: 196 deg. Intake / 206 deg. Exhaust
Lobe Separation: 109 Degree
Cylinder Heads: Cast Iron Vortec, 3/8” pressed-in rocker studs
Combustion Chamber: 64cc
Valves: .194” Intake/ 1.50” Exhaust
Rocker Arms: Stamped Steel, 1.5:1 Ratio
Valve Springs: 10212811
Maximum GM Recommended RPM: 5000
Ignition Timing: Base 10 degrees BTDC, 32 degrees total
• Fully GM assembled long block
• Stamped Steel Black OE Valve
• Oil pump, pick-up and oil pan
• Aluminum Performance Intake
• 12-3/4” Auto Trans Flexplate
• 8” Harmonic Balancer
• Front timing cover
• Cast Iron Long Water Pump
• Oil Filter Adapter
• Passenger Side RH Oil Dipstick and Tube
General Motors limited 2 year / 50,000 mile parts & labor warranty. Click on Document tab above for full details.