CMW Trucks - 1947 - 1972 Chevy Truck Parts


Share |



HT502 - Big towing power at an incredible value!

Nothing makes a towing job easier than 502 cubic inches of big-block torque maker! Our HT (high torque) 502 will give you all of the power you need to move mountains or pull your trailer up over a mountain. The GM Performance Parts HT502 has all of the same great performance characteristics of our other 502 engines, but it has been specifically designed for 1976-and-older trucks that need to tow or work hard.

The HT502 is stuffed with a 4.00" forged stroker crankshaft, 4.47" forged aluminum pistons, forged rods, and a roller camshaft. The deep-breathing iron cylinder heads, with their mid-size valves and oval-shaped intake ports, deliver maximum cylinder filling at a low rpm. Working together, this combination provides excellent low-end grunt with 512 lb.-ft. of torque coming in at only 2800 rpm.

The HT502 crate engine is delivered complete with an oil pan, valve train, valve covers, timing set, and balancer. You add an water intake manifold, carburetor, water pump, starter, and ignition system. All of these parts are available from your local GM Performance Parts dealer.

Possible Applications

  • Your big-block mud-bogger
  • A tow rig that needs an attitude adjustment
  • A pick-up truck that can pound 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

Chevy Performance 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, water 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.