ACCEL 31035 - Adjustable Vacuum AdvanceVacuum Advance - Adjustable - GM HEI Distributors - EachFully adjustable vacuum advance cannister for GM HEI distributorsThis unit permits a seamless wide range of adjustment to both amount and rate of ignition advance. This unit helps increase horsepower and throttle response. It provides maximum spark advance while preventing detonation or "pinging". This kit includes an allen wrench for easy adjustment along with instructions. Adjustable Vacuum Advance Increases Horsepower And Throttle Response Includes Allen Wrench For Adjustments Brand: ACCEL Category: Distributors Color: Silver Distributor Type: Accessories Emission Code: 3 Material: Steel part type: Distributor Vacuum Advance Product Type: Vacuum Canister Sub Category: Distributor and Magneto Warranty: Manufacturer's Limited 90 Day Warranty Weight: 0.7500