Here for your review is a genuine O.E. input and cluster gear set for Muncie 4 speed M21 with large countershaft 1966 -1970. Made by General Motors, cluster counts 27/22/19/17 tooth, GM part number of 3905465. Input count is 26 tooth with a GM part number 3925690. Ratios are 2.20 first gear, 1.64 second gear, 1.28 third gear and 1 to 1 fourth gear. Very nice cluster, input not so much.

ATTENTION: do not ask for shipping any other way than what is offered, we will not ship these heavy steel parts in some little mail envelope or flat rate thin no-good box just because you want it shipped cheap. We ship in new heavy box that will get this to you. Questions about alternate shipping will not be answered. If shipping fee seems too high, you can always drive here and pick it up if that seems more economical to you.