Not cheap-I believe P.I's shop, Pantera Performance Center in Colorado Springs, as does Gary Hall, the Byers brothers @ Precision Pro-formance and Marino Perna @ Pantera East in St Petersburg. In short, most of the usual vendors. Prices vary- some will not install their kit on a suspension that has weld-repaired axles, fearing failure of the weld and responsibility. This forces you into new stock or billet axles @ $650/pair extra. Others will sell you the parts, machine your carriers and let you assemble it on old axles. I did my own machining & assembly, & premium bearings & seals were over $100 for each side from a supply house.