well my mates at CJ pony say this
The 15" x 7" wheel is not recommended for use on the front of 1965-1966 Mustangs, as they do not have enough clearance from the factory for a 7" wheel in most cases. A 5" or 6" wide wheel is a safer alternative and generally recommended for the front.
The 15" x 8" wheel is only recommended for use on the rear of 1967-1973 Mustangs. It is not recommended for use on the rear of 1965-1966 Mustangs, as they do not have enough clearance from the factory for a 8" wheel without extensive modifications.
oh well looks like I wont be buying these then ....bummmer although the guy said they are off his 66 mustang