The key to towing performance is torque, and the HT 502 crate engine has got a whole lot of it. Not only does this crate engine make torque, but it makes it right where you need it, way down low. With 512 ft.lbs. of torque at an incredibly low 2800 RPM and 338 horse power at 4500 RPM, this engine will climb hills, accelerate onto the highway and pull out to pass with the sort of confidence that you?ve come to expect from a GM Performance Parts crate engine. Details: The key to towing performance is torque, and the HT 502 crate engine has got a whole lot of it. Not only does this crate engine make torque, but it makes it right where you need it, way down low. With 512 ft.lbs. of torque at an incredibly low 2800 RPM and 338 horse power at 4500 RPM, this engine will climb hills, accelerate onto the highway and pull out to pass with the sort of confidence that you've come to expect from a GM Performance Parts crate engine. So for not too much more than a rebuild of your tired big block tow motor, you can step up to an all new HT 502 developed specifically for towing and heavy vehicle applications in 20 and 30 series light duty trucks. If you're concerned about durability, don't be. We?ve used the same four bolt block that we use in our other high performance 502's, and filled it with a forged crankshaft, forged connecting rods, and forged pistons. It even has a steel roller camshaft, designed to work in perfect harmony with the high velocity cast iron cylinder heads. The heads, with their moderately sized valves and round intake ports, ensure maximum cylinder fill at low RPM, and that means excellent low RPM efficiency that equates to maximized low end power and torque. The 502 Truck Conversion engine comes assembled, but needs your intake manifold, carburetor, water pump and distributor to run. It's time to upgrade, and GM Performance Parts has your engine, the HT 502 is a High Torque workhorse that will get you, your trailer and your crew to the races without even breaking a sweat. The HT 502 is intended for 1976 and earlier Chevrolet and GMC 20-series and 30 series trucks. The HT 502 is not intended for use with electronic fuel injection. When used with electroniic fuel injection, under certain heavy load and high altitude conditions, engine damage may occur due to a lean fuel mixture condition. The HT 502 is not intended for marine use, and should only be used in 1976 and earlier pre-emissions street vehicles or any year off road vehicles. HT 502 Technical Information Horsepower 338 @ 4500 Torque 512 Ft. Lbs @ 2800 RM Max. Recommended RPM 5500 Compression Ratio 8.75:1 Block 10237292 Cast iron - four bolt main caps Crankshaft 10183723 Forged steel Connecting Rods 10198922 Forged steel Pistons 12533507 Forged Aluminum Piston Rings 12524293 Camshaft 12552296 Hydraulic roller Lift .480" I, .483" E. Duration @ .050" 204º I, 209º E. Timing Chain 3891519 Single roller Cylinder Heads 12552888 Cast iron - Round port 118cc combustion chambers Intake Valves 2.07" Exhaust Valves 1.73" Rocker Arms 12523976 1.7:1 Intake Manifold 12363407 Aluminum Holley flange Valve Lash Net lash Spark Plugs CR43TS Gap .035 #1 Rapidfile Gap .035 Ignition Timing 4º BTDC Technical Notes: Fully assembled, less intake manifold, distributor, water pump and exhaust manifolds. Includes engine asssembly, instructions and decals. Distributor P/N 1104067 or melonized distributor gear P/N 10456413 must be used on all crate engines with steel camshafts.