RE: Rims
You still might be getting stuck. Mark VIIIs have a 4.25 bolt pattern, and Mustangs are 4.5. I picked up some new take off Mustang Bullets pretty cheap assuming they would fit my Mark VIII, but no go. The did fit on my Mark III though, and look great on it worked out, but unless the Rs had a different bolt pattern, thats not going to work for ya.