The rule of thumb for power valve size selection is to divide your highest part throttle manifold vacuum reading by two and select the closest size smaller. Example: 8" Hg of manifold vacuum would use a 3.5" Hg power valve. Holley power valves include gaskets (thread size: 1/2-28).

Maximize engine efficiency and throttle response with Holley Power Valves—precision components that deliver the extra fuel your engine needs when it needs it most. These valves are engineered to work seamlessly within Holley carburetors, improving fuel flow during high-load conditions like acceleration or towing.

A properly functioning carb power valve is essential for maintaining the right air/fuel ratio under varying engine demands. Holley’s power valves are vacuum-activated, opening only when needed to enrich the mixture and prevent lean conditions that can damage your engine or hurt performance. Each valve is constructed with high-quality materials to resist blowout and ensure lasting reliability, even under demanding conditions.

Whether you're fine-tuning a street machine, dialing in a race setup, or restoring a classic ride, a Holley power valve provides consistent fuel delivery and enhanced drivability. With multiple vacuum rating options available, you can easily match the valve to your specific engine setup and driving style.

Engineered for compatibility with most Holley carburetors, these carburetor power valve components are easy to install and adjust, making them a favorite among performance tuners and weekend builders alike.

Don’t leave your engine’s performance to chance—upgrade to Holley Power Valves from JEGS and experience smoother acceleration, improved throttle response, and better fuel control. Shop now to get the precision your build deserves.