Adjustable Secondary Lever Kit

The Holley Adjustable Secondary Lever Kit (part number 26-137) is a precision carburetor linkage component designed for tuners and mechanics working with Holley four-barrel carburetors. This kit addresses a critical need in carb tuning: independent adjustment of secondary throttle blade opening relative to primary blade movement. Whether you're dialing in a performance street engine or fine-tuning fuel delivery characteristics, this secondary lever assembly provides the control to optimize throttle response and fuel economy.

The adjustable design features a slotted connection point that allows for changes in mechanical advantage and the opening curve of the secondary barrels independently of primary operation. This means you can delay secondary opening, soften the transition, or sharpen it—all without modifying the primary throttle circuit. Holley's engineering ensures the lever maintains consistent geometry under load, preventing binding and delivering repeatable, predictable secondary actuation.

This compact and lightweight assembly is ideal for installations in tight engine bay spaces without adding bulk. Mechanics and engine builders rely on this kit when transitioning to carbureted fuel delivery or upgrading existing Holley four-barrel setups, making it suitable for both stock-appearing restorations and high-performance builds.