1- set of top quality nylon replacement throttle shaft bushings for Holley performance carburetors. these hard to find nylon throttle shaft bushings are used on most Holley  muscle car and aftermarket performance vacuum secondary carburetors such as list # 1850, 3310. 80508, 83310 etc. These are not included in most rebuild kits and are almost impossible to find. Replace your worn out nylon bushings for a top quality rebuild without vacuum leaks around the throttle shafts for proper idle quality KIT INCUDES 4-.250" wide & 2-.125" wide X .015" thick bushings....enough for most 4 barrel carbs. NOTE: These are only to be used with throttle shafts that have machined recesses to accept these bushings. Please see our store listings for a huge selection of Holley parts.