Guys, I have acquired a Muncie trans that I can't determine what model it is as in M20, M21 or M22. The casting number is 3885010 and date code is P7C20 ( March 20, 1967). But from what I read there should be an A, B or C behind the date code that denotes what model it is and mine has none. Does anyone know what model I have?
Thanks