Ok, dodj, I think you are correct. I used a non digital micrometer and measured and it's like 2.8". Your number of 72.6 or roughly 7.3mm is the only measurement I have seen looking around. 73mm=2.87 inches which is close to what our hubs are so I'm hoping only a little "coersion" of the rim is needed.
So I tried to mount the rim and of course as expected it didn't fit over the hub. But what I did notice on the Mach 1 rim is a thin ridge of wheel material that is at the lip of the center hole of the rim that looks fairly easy to ground down.
Might go that route instead of tampering with the rotor hub especially as that is harder metal to deal with.
I'm going to document my measurements here in case my computer crashes again!
So as far as approximate primitive measurements go:
Challenger:
Hub width: ~2.8"
Hub height with grease cap: ~2.5"
Hub height alone: ~ 1 5/8"
Stud height: 1"
Mach 1 rim:
Center hole width: ~2.75?
Center hole depth to center cap: ~2 5/8"
From a Mustang site: "The 17x8 Bullitt wheels have the EXACT same dimension as your Mach 1 wheels. They are both 17x8 with a 5 3/4" BS with a 30mm offset."
Wheels 17 x 8-inch Magnum 500-style "Heritage Style" (5 spoke)
Tires Goodyear 245/45ZR17 Eagle ZR45
If those numbers from the Mustang site are right, I would need a 1.25" spacer to get the backspace to 4.5. I'll play with the center hole then measure the backspace need.
Time to get the file and grinder out!