Moroso Vacuum Secondary Spring Kit - Holley - 7 Springs

Moroso is well-known for making performance parts for racing and street applications. This vacuum secondary spring kit is designed to help you fine-tune the performance of your Holley carburetor. It gives you the ability to adjust when and how quickly the secondary throttle plates open, which can make a notable difference in how your engine responds under load.

Inside this kit, you'll find seven different springs. By swapping out the springs, you can change the vacuum signal required to open the secondary boosters. This allows you to dial in your carburetor for improved throttle response and better overall performance, especially if you've made other modifications to your engine. Getting the secondary opening just right can help prevent bogging or hesitation when you hit the gas.