center caps for 18" bullitt rims on mustangtuning
 

I was looking for new center caps since a buddy is willing to buy my old ones for 100$ lol. anyways i didnt know if it was 2 & 5/16 inch or 2 & 7/16 inch could someone point me in the right direction

http://www.mustangtuning.com/mustang...cessories.html

Anything with (Large Size) will fit..

yeah but that dont help, i guess i was not clear. i was looking at Saleen center caps from this site. http://www.haneymotorsport.com/Saleen%20Wheels.htm and they ask for 2 & 5/16 inch or 2 & 7/16 inch so i kinda need to know how big the ones are. since i dont have any tape w/ the 16th of an inch on it.