$ 4,259.95 $ 4,733.95
Part# HLY-550-822


These Holley Avenger EFI engine management systems are intended for users who want a bolt-on-and-go EFI system without the need for a laptop computer. The secret is the innovative Avenger EFI hand-held controller and the breakthrough technology of our self-tuning fueling strategies. The compact, easy-to-use controller guides you through the simple setup wizard, where you answer a few key questions about your engine setup. Once that basic information is loaded, you fire up the engine, run it through various rpm stages, and drive it to tuning perfection. The self-learning strategy will automatically tune your engine as you drive to deliver the optimum air/fuel ratios for performance and mileage

550-822 AVENGER EFI  Polished Stealth Ram™ SBC Multi-Port EFI for Early / Late heads
You’re sure to get some attention when you pop the hood and show an Avenger Stealth Ram™ Multi-Point EFI system! Available for traditional or Vortec headed SB Chevys, the Avenger’s Self-tuning capabilities make it easy as 1, 2, 3 to get your car up and running with EFI. The tunnel ram design of the Stealth Ram builds power in the upper RPM range while maintaining excellent mid-range torque as well.

550-822 AVENGER EFI Polished Stealth Ram™ system include:
Stealth Ram Polished intake manifold (idle-6500 RPM Power Band), 2 X 58 mm Throttle Body and 36 Lb injectors (up to 500 HP) ,  ECU, wiring harness, HEI ignition adapter, fuel rails, injectors, fuel pump and related small parts.

All you supply is a return line back to the fuel tank.


  • Instructions for Handheld
  • Instructions for Part# 550-822
  • Additional Instructions for Part# 550-822
  • Addendum for 550-822