Muncie ID
 

Picked this Muncie and ITM shifter up a couple weeks ago, can anyone tell me what it is?
From searching online it seems to have some conflicting characteristics.

Looks to be a 1969 trans with the casting number ground off should be a 660 case. The trans is a m20 2 grooves on input

And that is one of the things that is conflicting.
2 groove 10 spline input=M20 where the stamped number indicates M21
P = Muncie
9 = 1969
A = Janurary
02 = 02
B= M21

Wouldn't that be a 1970 or later side cover with the TCS switch on the 3-4 input?

Some one rebuilt it and changed the guts, opriginally was a M21

You could put a mark on the input and output shafts, put it in first gear, and if the output shaft turns 2 and a half times with one turn of the input shaft, that would be a M-20 (2.52:1 ratio). An M-21 would turn a little less then that, at 2.20:1.

If it has 2 rings on the input, you don’t need to turn it. There is no mix and matching of parts. It is a M20, period.

Thanks for the replies, it's kinda what I figured, born a M21 and somewhere down the line someone converted it into a M20, which is what I wanted in the first place.

Still puzzling is to why someone would grind off the main case part number?
I can't think of a reason for doing that.

Maybe it was out of a stolen car years ago and some one thought it was some kind of identification number

LOL, good thing it doesn't have a vin stamped next to the date code.....