New top quality OEM Holley primary throttle shaft for use on Holley model 4150 double pump and model 4160 vacuum secondary carburetors. will accept up to 1.75" diameter throttle blades. fits Holley and similar Avenger, BG, Demon, Grant, QFT, Street Avenger carburetors. Please see our store listings for more throttle shafts, throttle blades, blade screws, and large selection of base plate parts.