Wheel Spacers
 

Can you use wheel spacers on the front wheels of a 90 mustang?

- 8mm ones that just slide on...

you CAN, but you will probably need longer wheel studs, it might cause some rubbing, and don't be too surprised if you suddenly have horrible vibrations in your steering wheel.

You are better off using a rim with the correct backspacing. Spacers present the possibility for you to be on the interstate at 75 mph and watch your rim pass you at 85 mph. What rim are you looking at? What spacer are you looking at? 5 lug rim? Have you converted the car to 5 lug? 99% of the reason to convert to 5 lug is for rim availability.

like previously said you can and will need longer wheel studs. I used 1/4" spacers on the front to put the stock 06 rims until the cash flow increases.
here is a place for longer studs, I recommend the 3" from moroso and if I remember correctly it was a .615 knurl

http://www.latemodelrestoration.com/...q=wheel%20stud