This Eastwood Complete Manual Transmission Kit includes all necessary bearings, seals, gaskets, synchronizers, springs, and bushings needed to rebuild your Muncie M20, M21, with 10 spline input and 27 spline output shafts and 7/8in. diameter countershafoot Designed specifically for 1964-65 casting number 3851325. A detailed exploded view is included. Factory shop manual suggested - professional installation recommended. Made in the USA.