Holley Fuel Injection Throttle Body Adapter

Holley EFI Throttle Body Adapters: Bridging Platforms, Unlocking Builds

Engine swaps and modern EFI conversions are at the heart of today's performance builds — and few obstacles are more frustrating than mismatched throttle body flanges. That's exactly the problem Holley solves with its lineup of fuel injection throttle body adapters. Engineered by the same company that has been defining fuel-system technology since 1903, these adapters are purpose-built to make cross-platform EFI installations clean, reliable, and leak-free.

What Holley Throttle Body Adapters Are Designed to Do

A throttle body adapter bridges the gap between an intake manifold's bolt pattern or flange size and the throttle body being used — a critical need any time you're mixing and matching platforms. Whether you're fitting a GM LS throttle body to a Mopar Gen III Hemi intake, adapting a 4150-flanged manifold to a modern drive-by-wire unit, or mounting a Ford GT500 throttle body to a low-profile 7.3L “Godzilla” intake manifold, Holley has a targeted solution.

One of Holley's most notable offerings in this space is the Holley EFI Throttle Body Adapter Plate (Part #300-660), which adapts a 95mm GM LS throttle body intake flange to an 80mm Mopar Gen III Hemi throttle body — a swap combination that has surged in popularity among builders pushing Hemi-swapped platforms to new horsepower levels. Holley also produces billet aluminum adapters that mate a 4150-flanged intake manifold to either a 92mm or 105mm LS drive-by-wire throttle body, solving one of the most common headaches in the LS swap world.

Why Holley Stands Out in This Category

Precision machining and materials. Holley's throttle body adapters are crafted from billet aluminum, ensuring dimensional accuracy that eliminates vacuum leaks and maintains proper throttle plate alignment — both critical for stable idle and accurate fueling under Holley EFI engine management.

System-level integration. Because Holley engineers the throttle bodies, intake manifolds, and EFI systems that these adapters connect to, their fitment is validated across the entire ecosystem. There's no guesswork about whether the adapter will interfere with IAC provisions, TPS sensor wiring, or drive-by-wire actuator clearances.

A legacy of fuel-system authority. Holley has been at the cutting edge of fuel delivery since the early 1900s, and today that expertise extends across the entire EFI spectrum — from Sniper and Terminator X throttle body systems to the Hi-Ram and Lo-Ram intake manifold families. Throttle body adapters are the connective tissue in this ecosystem, and Holley treats them with the same engineering rigor as the major components.

Who These Adapters Are For

• LS swap builders needing to fit modern drive-by-wire throttle bodies to traditional 4150-flanged intakes
• Mopar/Hemi enthusiasts running LS-style intake manifolds on Gen III Hemi engines
• Ford 7.3L “Godzilla” builders looking to upgrade throttle body options on Holley's Low-Profile intake manifold
• EFI conversion builders integrating Holley Sniper or Terminator X systems with non-stock intake combinations

If you're building a custom EFI setup and need to connect throttle body hardware across different platforms, Holley's purpose-engineered adapters are an essential piece of the puzzle. Browse the full selection of fuel injection throttle body adapters or explore everything Holley has to offer across their complete EFI and fuel-system lineup.