Mustang have a 4.5 and thunderbirds have 4.25. You either have to do a mustang hub swap or get 5*4.25 rims. There is a set on the for sale that are new on the parts for sale and painted a nice grey/titaniam. Cudaz has a rim wheel shop and has nice different rims for sc's. Tbird rims are more expensive as there is less of a market as opposed to the large mustang market with cheaper rims. That's why some go for the mustang hub swap. That and getting to upgrade size of front brakes to cobra brakes and larger rotors. There were very few cobra rims made with sc bolt pattern originally. But you can find some aftermarket ones.