T125/70D16 is the tire size. What you hare having an issue with is most likely the rim itself? The original spare should fit front or rear. Sounds like someone swapped the calipers/brakes out on the fronts. Have any pictures?
@fox owner - Can you verify that your spare rim is actually 16"? Trying to make sure you didn't somehow end up with a 15" spare from an earlier Fox. Most likely a caliper change though....
T125/70D16 is the tire size. What you hare having an issue with is most likely the rim itself? The original spare should fit front or rear. Sounds like someone swapped the calipers/brakes out on the fronts. Have any pictures?
Yeah, that might have come on and early 80's Escort or some compact like that but not an 87 and up Mustang. I'd say it might fit a 10" front brake car but I have no clue.