Chevy HT502 Truck Crate Motor

Big block HT 502 truck motors deliver the power and massive torque you need to pull heavy loads with your older GM truck. The HT502 brings a mountain moving 512 lb.-ft. of torque coming in at only 2800 rpm, which is perfect for a pulling truck. This big block has been specifically designed for 1976 and older GM trucks.

Internals are quality components with a 4.00" forged stroker crankshaft, 4.47" forged aluminum pistons, forged rods and a roller camshaft. Cast iron cylinder heads give great performance for the money! With their mid-size valves and oval-shaped intake ports, these heads deliver maximum cylinder flow at a low rpm. This engine is made for pulling and reflects that in the torque ratings!

HT502 crate engines come with an oil pan, valve train, valve covers, timing set, and balancer. You add your intake manifold, carburetor, water pump, starter and ignition system.

Possible Applications

  • Your big-block truck
  • Massive towing
  • A pick-up truck that kicks most sports cars

*Applications have not been validated. They are merely suggestions of how you might enjoy your GM Performance Parts crate engine. Some applications may affect engine warranty. See specific warranty information. Some applications may not be emission legal; check state and local ordinances.

Engine Part Number 88890534
Displacement (cu in): 502
Bore x stroke (in): 4.47 x 4.00
Block (P/N 10237292): Cast iron with 4-bolt main caps
Crankshaft (P/N 10183723): Forged steel
Connecting rods (P/N 10198922): Forged steel, shot peened
Pistons (P/N 12533507): Forged aluminum
Camshaft type (P/N 12552296): Hydraulic roller
Camshaft lift (in): .480 intake / .483 exhaust
Camshaft duration (@.050 in): 204'c1 intake / 209'c1 exhaust
Cylinder heads (P/N 12552888): Iron round port; 118 cc chambers
Valve size (in): 2.07 intake / 1.73 exhaust
Compression ratio: 8.75:1
Rocker arms (P/N 12523976): Stamped steel
Rocker arm ratio: 1.7:1
Flexplate (P/N 10185034): 14"
Recommended fuel: 92 octane
Ignition timing: 4'c1 BTDC
Maximum rpm: 5500

HT 502 engine image

Part #: 88890534

HT 502 dyno image

  • NOTE: Distributor with melonized steel gear MUST be used with long blocks and partial engines with steel camshafts, or engine damage will occur. GMPP distributor P/N 93440806 is recommended.
  • Designed for pre-1977 street vehicles, or any off-road vehicle.
  • Requires the addition of carburetor, intake manifold, water pump, starter, distributor and ignition system.
  • Clutch linkage boss is cast into block, but must be drilled and tapped. When using cast iron exhaust manifolds, lower head bolts may need to be replaced with bolts with shorter heads, for clearance.
  • Requires electric fuel pump because the Gen VI block has no mechanical pump boss.
  • Comes with an externally balanced 14" automatic transmission flexplate; use externally balanced flywheel P/N 14096987 and 11" clutch assembly for manual transmission.
  • Not intended for electronic fuel injection because heavy loads and/or high altitude condition could cause lean fuel mixture.
  • Not intended for marine applications.