512840 O-ring intake manifold conversion kit

If you are tired of the vacuum leaks common with the old plumber-style intake manifolds, this O-ring conversion kit is the solution. It allows you to upgrade 1940 to 1954 1200cc Knucklehead and Panhead engines to the much more reliable O-ring sealing system used from 1955 to 1965. This kit includes the steel screw-in adapters needed to modernize the intake tract of 1940 to 1948 74-inch Knuckleheads and 1948 to 1954 74-inch Panheads. By moving away from the old brass nut and packing style, you get a more consistent seal that helps stabilize your idle and overall engine performance. It is a must-have for any rider who actually puts miles on their vintage Big Twin.