I'm having some trouble trying to figure out exactly which 4 speed I have here. There are 7 side cover bolts, the casting number on the main case is 3925656, the stamp on the case is R0M13, tail shaft housing casting number is 352254, side cover casting number is 6261888, the date code is F269 and VIN stamp is 2A7504377. I was fairly certain it was a Saginaw trans, but I am seeing conflicting info with the "R" code as it appeared to have changed designations from 68-earlier Saginaw to 69-later Muncie.

If it's iron and there are 3 shift levers on the side cover it is a Saginaw.

from www.nastyz28.com (http://www.nastyz28.com/)
Camaro Manual Transmission Component Casting #'s.
Type Years Main Case Extension Side Cover
Saginaw 4-Spd (IRON) 1970 - 1972 3925656 3873886 3952647
1973 - 1975 3925656 326558 3952647