My 1975 Ghia came with CR70-13 tires. Rims are 13 x 5 with 4 bolt pattern. The Mustang specs do not list a 14" option for 1975. I have found a set of 14" x 6" chrome rims from a 1979 Mustang. Will they fit and what size tire do I use to make sure I don't screw up the speedometer readings.??