Tony, have the 10" wheels been checked for clearance over the GT-500 14" Brembos? Still looking out for reasonably priced 18x10s that will work on all 4 corners for my friend's 07 GT with Brembos added that he uses for track days.
former original owner -- 87 Mustang LX 5.0 hatchback
07 Mustang GT with some stuff
88 Thunderbird Turbo Coupe