Muncie H. Duty 3 speed trans. with 5 mounting bolts cast number 6273262 . It turns and shifts all gear nicely and Looks good inside . It is missing the front bear retainer .
I believe these optional HD transmissions where used late 1960's and up thru the 1970's and available in C-10 20 and 30 models . $175 and must be pick up here near Richmond ,VA. Email me for more info. bwbugay@aol.com