Holley EFI Fuel Injection Throttle Body Adapter

Holley EFI Throttle Body Adapters: Bridging Modern EFI to Any Platform

Few names carry as much weight in the world of electronic fuel injection as Holley EFI. From the NASCAR pit lane to weekend hot rod builds, Holley has spent decades developing EFI hardware that spans street, strip, and everything in between. One of the most practical — yet often overlooked — pieces of that puzzle is the fuel injection throttle body adapter. These precision-machined components are the critical link that allows builders to mix and match throttle bodies and intake manifolds across platforms that were never originally designed to work together.

What Holley EFI Throttle Body Adapters Do

Engine swaps, platform conversions, and EFI upgrades rarely involve hardware that lines up perfectly out of the box. Bolt patterns, bore sizes, and flange standards can differ dramatically between manufacturers and generations of engines. Holley EFI throttle body adapters solve this mismatch problem with components engineered specifically for real-world swap scenarios.

A prime example is the Holley EFI Throttle Body Adapter Plate (Part #300-660), which bridges a 95mm GM LS throttle body intake flange to an 80mm Mopar Gen III Hemi throttle body — enabling one of the most popular cross-platform swaps in the performance world. Similarly, Holley EFI's billet aluminum throttle body adapters easily adapt a 4150-flanged intake manifold to either the LS 92mm or 105mm Drive-By-Wire throttle body, making them indispensable for builders running modern DBW systems on classic or custom intakes.

Broad Coverage Across Platforms

Holley EFI's throttle body adapter lineup covers a remarkable range of applications:

• GM LS Swaps: Adapters that convert 4150/4160 square bore flanges to 92mm LS Drive-By-Wire throttle bodies, as well as intake elbows that fit GM LS throttle bodies in multiple finishes.
• Mopar Gen III Hemi: Adapters supporting Gen III Hemi EFI in configurations for 95mm LS-style, 80mm, 92mm, and 105mm LS-style throttle bodies, fitting 2009-up 5.7L, 2005–2010 6.1L, and 2011-up 6.4L engines.
• Ford Applications: Dedicated throttle body adapters such as the Ford 7.3L Low-Profile Intake Manifold adapter, which allows fitment of a 2020–2023 Ford GT500 throttle body to Holley's Low-Profile 7.3L "Godzilla" Intake Manifold.
• 4150/4500 Flange Conversions: Billet aluminum adapters for running large-bore LS and DBW throttle bodies on traditional 4150 and 4500 Dominator-flange intake manifolds.
• Throttle Body Angle Adapters: Angle adapter solutions that fit GM LS, LT, and Gen-V LT4 intake manifolds, letting builders manage packaging constraints in tight engine bays.

Why Holley EFI Stands Apart

Holley EFI is the premiere standalone EFI option today. That reputation extends directly into their throttle body adapter lineup. Rather than treating adapters as an afterthought, Holley engineers them to the same tolerances as their throttle bodies and intake manifolds — ensuring that the entire air-charge path remains sealed, efficient, and properly oriented. Materials are primarily billet aluminum, offering both dimensional precision and long-term durability in high-heat underhood environments.

Because ARCA, NASCAR trucks, NHRA Pro Stock, and more all utilize Holley EFI for their tuning needs, the engineering behind even these "connector" components reflects genuine race-proven standards. Whether you're an engine swapper looking to mate a modern throttle body to a legacy manifold, or a racer optimizing airflow orientation for chassis clearance, Holley EFI has a purpose-built adapter to get the job done cleanly.

Browse the full selection of Holley EFI fuel injection throttle body adapters to find the right fitment for your LS, Hemi, Ford, or custom build — and pair them with Holley's broader EFI ecosystem for a complete, cohesive system.