ATK HP94C-EFI Chevy 383 with Fitech EFI 415HP

Fuel injection meets ATK's 383 stroker on the HP94C-EFI, a FiTech-equipped combination that puts out 415 hp paired with 460 lb-ft of torque, with the EFI unit itself rated to handle up to 600 hp of headroom. A wiring harness and handheld tuner ship alongside the throttle body.

What to plan for

No fuel pump comes with the package, so budget for an electric pump or a mechanical pump run through a FiTech Fuel Command Center. This EFI setup also needs a dedicated ignition box of its own, which is easy to miss when pricing out the swap. The oil pan, timing cover, a water pump, a harmonic balancer, and a flexplate all ship installed, along with a dual-plane intake and an HEI distributor.

Inside the stroker

Forged internals carry this combination: Scat's nodular-iron crank and matching I-beam rods, bolted up with ARP hardware, sit beneath ATK's own aluminum heads and hypereutectic pistons at 9.7:1 compression, with a double roller timing chain. Displacement comes from the same bore-and-stroke pairing ATK uses across its 383 family, and the engine is dyno tested before it ships.

Q: What does the FiTech system include? The throttle body, wiring harness, and a handheld tuning unit; a fuel pump and ignition box are not part of the package.

Because the throttle body and handheld tuner ship together, most of the wiring questions that come with a standalone EFI kit are already settled before the crate arrives.