This is the best Muncie transmission case made. Let us say that again, "This is the BEST Muncie transmission case made" These cases use a full width 307 sealed bearing in the front, not the old narrow N1307L bearing that the originals had. That thicker front case area also allows for added support to the countershaft which also has a welsh plug to seal it as well. Much thicker overall, and cast from the finest aluminum available today. Extension housings, shift covers, ductile iron midplates, gearsets, and any other parts you may need to build the "Toughest" Muncie available are here at RiversideGear, in stock, ready to put to work.