My old '66 Commando/4sp Barracuda (October 1965 SPD) still had a 7-1/4 in it when I got it in late 1980. Previous owner was a friend of mine who got it in 1975. By the end of 1981 it had an 8-3/4 3.23SG.
I really like this car, but I'm not in the market for anything...