ATK HP36M Chevy 383 Stroker Mid Dress Engine 435HP

The ATK HP36M is the mid-dress tier of ATK's 435 hp, 475 lb-ft 383 stroker, built with AFR's aluminum heads once again, 72cc chambers, 180cc ports, and the same 2.02/1.60 valve sizing, over forged 10:1-compression pistons.

What mid-dress means here

Scat's crank-and-rod pairing, nodular iron on top and forged I-beam below, forms the bottom end, bolted with ARP 8740 hardware. Oil pan, timing cover, and harmonic balancer are all installed on this tier, along with the Edelbrock dual-plane intake, distributor, and water pump.

Parts left for the installer

• The carburetor and fuel pump stay off the engine, named only as ATK's suggested parts.
• Spark plugs and plug wires are likewise left for the installer to supply.
• Confirm exact ignition parts shipped with us before ordering.
• Fuel of 91 octane or higher suits this compression and cam combination.

Common questions

Which parts are already in place? The balancer, intake, distributor, and water pump; fueling and ignition parts are not.

What's different from the complete HP36C? The complete build adds the carburetor and ignition consumables that this mid-dress version leaves for the installer.

What's the compression ratio? 10:1, the same figure as ATK's base and complete HP36 builds.

What heads top this engine? AFR's aluminum castings, with 72cc chambers and 180cc ports feeding the intake side. California requires BAR compliance for engine swap installations.