An Affordable, High Performance Alternative to Rebuilding
If you’re thinking about repowering your trusty Big-Block-powered truck, don’t bother with a rebuild or a reconditioned used engine. Chevrolet Performance’s HT502 crate engine is an affordable alternative with more power and greater durability.

The HT502 is rated at 377 horsepower and a whopping 512 lb-ft of trailer-tugging torque. That’s more than the factory ever offered and more than you’ll get with a stock-type rebuild. It is uniquely suited to pre-1978 trucks, but is adaptable to a variety of applications.

We build the HT502 with a forged crankshaft, rods, and pistons for maximum strength, and they’re installed in a new version of the Big-Block cylinder block. It is updated for greater strength and performance capability. A conservative 8.75:1 compression ratio ensures pump-gas performance at all altitudes and engine loads.

Our assembly comes with heads and a balancer installed. An induction system, ignition, starter, water pump, and other accessories are required to finish the engine. All necessary components are available from Chevrolet Performance.

HT502 TECH SPECS
Part Number: 88890534
Engine Type: Chevy Big Block V8
Displacement (cu. in.): 502
Weight: 557
Horse Power: 377
Torque: 512
Trans*: C
Bore x Stroke (in.): 4.47 x 4.00
Block (P/N 19170540): Cast Iron with 4-Bolt Main Caps
Crankshaft (P/N 10183723): Forged Steel
Connecting Rods (P/N 19170198): 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° Intake / 209° Exhaust
Cylinder Heads (P/N 12562917): Iron Oval Port; 118-cc Chambers
Balanced: External
Valve Size (in.): 2.070 Intake / 1.730 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: Base 4° BTDC, 26° Total
Maximum Recommended Rpm: 5500

INSTALLATION NOTES

• Requires the addition of carburetor, intake manifold, water pump, starter, distributor and ignition system (not included)
• Clutch linkage bosses are now drilled and tapped. When using cast-iron exhaust manifolds, lower head bolts may need to be replaced with bolts with shorter heads for clearance
• 502 engines now have a mechanical fuel 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 applications
• Designed for pre-1976 street vehicles or any off-road vehicle
• Not intended for marine applications

HT502 Warranty Detail PDF