Fuel Air Spark Technology, more commonly known as FAST, developed its EZ-EFI system to take all of the hassle and trepidation out of adding EFI to a carbureted vehicle. Bolting on in place of a standard four-barrel carburetor, the FAST EZ-EFI system features patented self-learning control strategies and requires the user to answer a few basic questions via the hard-wired LCD hand-held display module. With a four-wire hook up (optional wires for A/C idle speed, cooling fan, and fuel pump), it couldn't be easier. The EZ-EFI throttle body ships fully assembled and bolts on in minutes. Just plumb your return-style fuel system, mount the ECU, and install the included wideband O2 sensor and you're ready to roll. Options include internal and external fuel pump kits, dual-quad upgrade kit, fuel hose kit, in-vehicle mount for hand-held controller, and electronic transmission controller for modern overdrive electronically controlled transmissions.
The folks at Holley have been designing fuel distribution systems for engines of all types for over 100 years. Holley's carburetors have been OE at one point or another on many factory performance Mustangs and even sat under the air cleaners of early Fox Mustang GTs (with five-speeds). Holley's foray into EFI has been a long-travelled road and not something they just decided to jump into as a "me too" business. Holley's latest EFI products feature a more traditional "TBI" style throttle body with injectors directly over the throttle plates, just like the OEs used to do it. The Holley Avenger EFI systems are direct replacement EFI units for carbureted intakes, of course, and as such bolt right on to a standard 4150 flange. Holley offers three different throttle body kits depending upon your engine's horsepower level and the kits are surprisingly complete. No laptop is needed either, as the hand-held full color tuner allows for quick and easy setup, and the self-learning ECU combined with the included wideband O2 sensor means no tuning knowledge is required to be up and running in no time.