I am restoring a 69 Mach1 and it curently has an 8" rather that the 9" that it is supposed to have. I have aquired a complete rear for a 70, Nodular center section, traction loc, etc...
I am not restoring the car to 100% origional but am curios of the diff. between the 69 & 70 housings. I know they both are the same width and the spring purches are in the same locations. I do know that the exhaust on a 69 and 70 are different and wonder it this changes the location of the vent etc...
The 69-70 housings are most likely exactly alike, the only difference my be the axle vent itself, I think it's integrated with the brake line block on the 70. Shouldn't affect the exhaust routing though.
That was about all I could remember, was hoping for a bit more detailed info. The car is not going to be 100% correct but I want it to be as correct as possible. Not too worried about date codes etc...