I couldn't get them to work on my last truck (a '99 2500) because of the brake calipers. I didn't want to grind them as much as was necessary to allow the centramatics to fit.
Incidentally, I bought them because of all the good stories I had heard about them. Too bad they wouldn't fit my truck.
There's another product out there that actually goes IN your tires. It's called Equal and works just as well.
HTH.
Duane