I know the 67-70 9-inch is a larger tube than the 65-66 9-inch, it did not have the dramatic taper the early ones did. But are you sure that is also true of the 8-inch?
I just dropped my 67 8-inch out to replace with a 9, so I've got one on the floor in my garage if you need measuring (or pricing ).
Yes. At the time I built the Fastback, I also had an original 67 "C" code 289 auto Mustang Coupe. It had the 8" rear and the axle tubes were the larger type (2 7/8").
Yes. At the time I built the Fastback, I also had an original 67 "C" code 289 auto Mustang Coupe. It had the 8" rear and the axle tubes were the larger type (2 7/8").
From my own experience, I would have to say yes. Another piece of evidence is that Mustangs Unlimited offers U bolts and shock plates for 67 - 70 Mustangs for all models (except staggered shocks). The part no for the left is F1604 and the right is F1603. There is no distinction made between 8" or 9" rears.