Mechanical Secondary Linkage Connecting Rod- 4150 & 4010 Carburetor- Fits Holley Mechanical Secondary Linkage Connecting Rod - Fits: Holley Specs: *Sold as a Single Kit and Includes (x1) Connecting Rod, (x1) Cotter Pin, (x1) Washer *Stock Progressive Style Linkage *Use This Kit to Connect the Secondary Throttle Shaft To The Primary Throttle Shaft, Which Will Open The Back Two Carburetor Barrels *Fits Mechanical Secondary 4150 Series Holley Carburetors *Fits Holley & Holley Style Carburetors Including AED, Barry Grant, Quick Fuel, Demon, Avenger, Etc.. *Part Will Come In Bulk Style Bag / Box Packaging