These new gaskets fit 4160 series 600 CFM Holley 4 barrel carbs with vacuum secondary, 1-9/16" throttle bores and no removable jets in the secondary. LIST # 1850/1-8^, 1850 S^ & SA^ ONLY. Holley Rebuilder Carb Rebuild Kit For 600 CFM Vacuum Secondary 2 X 4.
