4-BBL TBI Kits

If you can install a 4-bbl Holley carburetor you can install one of the Holley 4-BBL Throttle Body Injection (TBI) fuel injection kits. These kits are designed to be a direct bolt-on to square flange intake manifolds, or use the optional manifold adapter to use with spread bore manifolds. Choose from the ease of hand-held controller setup of the Holley Avenger 4-barrel TBI fuel injection kits or the more advanced technological capabilities of the Holley HP 4-barrel TBI fuel injection kits.

The Holley Avenger 4-BBL TBI Fuel Injection Kits offer three different horsepower ranges to choose from. The 200-400 HP kit includes a 700 cfm TBI unit with 65 pound per hour injectors. The 375-525 HP kit includes a 900 cfm TBI unit with 75 pound per hour injectors. And the 450-600 HP kit uses the same 900 cfm TBI unit but with 85 pound per hour injectors. They come complete with absolutely every part you need for installation, other than a bit of fuel hose and, in some cases, metal fuel line.

The Holley HP 4-BBL TBI Fuel Injection Kits are available in two ranges. Both feature the 900 cfm Holley 4-BBL Throttle Body Injection (TBI) unit, but one has 75 pound-per-hour injectors (supporting up to 525 HP) and the other has 85 pound-per-hour injectors (supporting up to 600 HP.) While the Avenger Fuel Injection Kits include a fuel pump, the HP Fuel Injection Kits do not include the fuel pump. (Visit the Fuel Pumps and Filters section to learn about our recommendations on EFI fuel pumps.) Like the Avenger kits, the HP kits let you source your own fuel hose and fuel line (as required by your specific application.)

Regardless of which Holley 4-BBL TBI Fuel Injection Kit you select, installation is straight-forward and can generally be accomplished with a typical mechanic's set of hand tools. To summarize, after removing the existing carburetor, you start by bolting the Holley TBI unit in place, using the same linkages as the carburetor. The low-pressure carburetor fuel pump must be replaced with the EFI fuel pump and the plumbing completed for that. A few sensors must be put into place, including the Wideband O2 sensor, Intake Air Temperature sensor, and MAP sensor. Finally, the ECU itself is located and wired in place with the use of the included harness kit. Be sure to check out our Instructional Videos we have provided to get a visual on what is required.

Use this table to help select the right Holley Avenger or HP 4-BBL TBI Fuel Injection Kit for your application:

It is highly recommend that you review the installation instructions for the various Holley EFI Systems you are considering prior to making a purchase decision.

• Holley Avenger 4BBL TBI Fuel Injection Systems Installation Manual
• Holley HP 4BBL TBI Fuel Injection Systems Installation Manual