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.
Chevy Big-Block V-8
Displacement (cu. in.):
Bore x Stroke (in.):
4.47 x 4.00
Block (P/N 19170540):
Cast-iron with four-bolt main caps
Crankshaft (P/N 10183723):
Connecting Rods (P/N 19170198):
Forged steel, shot peened
Pistons (P/N 12533507):
Camshaft Type (P/N 12552296):
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
Valve Size (in.):
2.070 intake / 1.730 exhaust
Rocker Arms (P/N 12523976):
Rocker Arm Ratio:
Flexplate (P/N 10185034):
Base 4° BTDC, 26° Total
Maximum Recommended rpm:
Already own one, but lost some of the paperwork? We’ve got you covered with downloads and links for some of the more important documents below. You’ll find everything from the vital data about your engine’s capabilities to how to install it into your build, even all of the warranty information should you need to make a claim. And don’t forget, the best way we can make sure to get you the latest information on your specific part is to tell us which one you have by registering your engine. No matter what stage of your build you’re in — from shopping for the right part to that part having turned in a few miles — we have the information you need.
Download a catalog for a full listing of components and related parts.
* The Manufacturer's Suggested Retail Price excludes destination freight charge, tax, title, license, dealer fees and optional equipment. Click here to see all Chevrolet vehicles' destination freight charges. Click here to see the 2015 City Express destination freight charge. Click here to see the 2015 Colorado destination freight charge.
***The Manufacturer's Suggested Retail Price excludes tax, title, license, dealer fees and optional equipment. Includes destination freight charge and gas guzzler tax.
Unless specifically noted to the contrary herein, vehicles equipped with Chevrolet Performance Parts may not meet Federal Motor Vehicle Safety Standards and emissions regulations and should not be operated on public roads. Chevrolet Performance customers are responsible for ensuring their use of Chevrolet Performance complies with applicable federal, state, and local laws, regulations, and ordinances. Many parts intended for racing or other “off-highway” use are not designed or tested for crashworthiness or to meet the safety needs of the motoring public, and may adversely affect the original intended performance or handling characteristics of the vehicle. These parts are designed and intended to be used with experts supervising their installation and use, to help assure the proper and safe operation of the vehicle.
To allow you to do an accurate price comparison with prices featured on other Internet sites, GM provides Internet pricing both with and without the Destination Freight Charge (see prices including Destination Freight Charge below). To get full pricing details, go to our Build Your Own section.