This conversion kit provides the parts needed to convert your engine to use the HIF38  1.5" SU carburetor on your small bore  engine, or a 1275 for fuel economy. The kit includes a rebuilt carburetor, needle, intake manifold, air cleaner, spacer, throttle cable and neccessary hardware. The rebuilt carb. will comes with all new seals, gaskets, needle & seats, and jet tube.  All parts are inspected, ultrasonically cleaned, and polished. This is a great upgrade from the HS4  SU carb, and far superior thatuses the internal float, sealed throttle shaft, and easier to use screws to adjust the carb.