Thanks guys I scored a set of A-Body disc spindles, dust shields, bolts from a 1974 A-Body. Dave, the caliper adaptor kits form AR Eng. are for either early or late model Viper calipers with 2003 being the changeover point. I was interested in the 2003 on up Viper kit which use 73-76 A body or 73 up E-Body disc spindles. Adrian, I found out the aftermarket uses castings which are plenty strong, but the original factory spindles are drop forged steel, cant beat that!
Dave is an advocate of the original chassis parts as am I, but sometimes there are stronger parts out there, you just have to shop very carefully.