The stock bullit rim is (according to fordracing.com)
http://www.fordracingparts.com/parts/part_details.asp?PartKeyField=7868
M-1007-T178S*
Fits 2005 Mustang
5-Lug 4.5" bolt circle
6.295" backspacing
17" x 8" wide
Now I can tell you first hand that this 6.295 measuremt is...
