Do You Have 17" wheels on it right now?
In 2003:
The V6 came from the factory with 225/55R16
The GT and Mach I came from the factory with 245/45R17
The Cobras came from the factory with 275/40R17
In Short YES it will work on a 17 inch wheel but it is really skinny
205/50R17 - Width: 8.07" Diameter: 25.07 (When your speedo reads 65, you will be doing 63)
225/55R16 - Width: 8.86" Diameter: 25.74
245/45R17 - Width: 9.65" Diameter: 25.68 (When your speedo reads 65, you will be doing 64.85)
275/40R17 - Width: 10.83" Diameter: 25.66 (When your speedo reads 65, you will be doing 64.80)