8 1/4 didn't replace the 8 3/4 in A-bodies until 1973.
I also have an unmolested Swinger with a 318/904 with an 8 3/4. Bought it with 27,000 miles on the clock so it's original.
I have purchased 2 1972, 6 cyl, 4-door Darts with 8 3/4s in them, just to get the rear drum to drum. I think when...