Thanks guys for chimming in. If I had my choice, I would not use any spacers, but my centers were already cut and powder coated. I need the 10mm to clear the SRT brakes. The rears are fine. Dave sells longer lug nuts but the wheel manufactorer said that it will not work with the neck. Or that is what I was told. They recomended I change the studs to longer ones by 10 to 15mm longer. We were going to measure the amount of exposed thread but your info helps out alot. If you are getting barley enough with 6mm then for sure 10mm will not work...........Anybody else know the stock length of the studs. I have no way of checking cause I do not have the car with me right now.