ATK Engines HP94 Small Block Chevy 383 Stroker Base Engine, 415HP

ATK's HP94 long block puts the bare essentials of a Chevy 383 stroker on the pallet: 415 hp and 460 lb-ft of torque from a 4-bolt main OE roller block, aluminum cylinder heads with 2.020 in. intake and 1.600 in. exhaust valves, and a hydraulic roller cam, with the induction and ignition left for you to choose.

Who this engine suits

Down in the block, a Scat nodular-iron crankshaft turns Scat's forged I-beam connecting rods, both secured with ARP 8740 bolts, under hypereutectic pistons running 9.7:1 compression. Billet aluminum 1.6-ratio roller rockers work the valves, and a double-roller timing chain and 110-degree lobe separation cam are matched to the 4.040 in. bore and 3.750 in. stroke. Because this is ATK's base long block, the intake manifold, carburetor, distributor, water pump, and balancer are not on the engine; they stay on ATK's suggested parts list for the builder to add.

Before you order, check this

• This block is sold as year- and model-specific, and cores are returned directly to ATK rather than to a third party.
• A Melling standard-volume oil pump and rear-sump oil pan handle lubrication on this build.
• Firing order and plug gap are set to ATK's spec sheet, so pull those figures before you set up ignition.

Common questions

Does it come with a carburetor or intake? No, those along with the distributor and water pump are left for the installer on this base build.

What cam is in it? A hydraulic roller, ground for a 110-degree lobe separation to suit the 383's stroke.

Is the balancer installed? No, ATK lists a balancer only as a suggested part on this base long block.