"I ordered a 14-bolt kit with the newer style slide-on rotors for a 1998 C3500 after experiencing so many problems with broken adjuster hardware, broken springs, overheated drums, and overall crappy braking with back drums. The kit installed easily and everything works great, but I had to grind down the backs of the calipers to make them clear the stock 16" aluminum Chevy rims. These rims did not come on the truck, and are actually for newer body-style trucks. No big deal, a 40 grit flap disk did the trick. I will be ordering kits for my 1989 C3500, 2000 C3500 and 1981 D350. No more drums! "