Chevy HT502 - Emission Legal Truck Conversion Kit

HT502 big block crate engines are made to convert 1991-93 Chevrolet and GMC 10-, 20-, and 30-series 2 wd trucks originally with a 454 TBI engine and 4L80E automatic overdrive transmission. HT502 kits provide better towing capabilities in a direct bolt-in replacement for any high-mileage 454. Truck drivers with older 454 engines will love the towing power from a new 502!

The HT502 is meant as a replacement. You swap over your induction components like TBI manifold and throttle body along with ignition system and some other components. A new GM PROM electronic control module (ECM) chip is included, along with a detailed instruction guide.

Technical Note: This kit will not work on four-wheel drive trucks, due to an exhaust interference.

Possible Applications

  • Your big-block truck
  • Better towing
  • Pickups that can beat many 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 88890533
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 #:88890533

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.
  • Technical Note: This kit will not work on four-wheel drive trucks, due to an exhaust interference.