Yes the 6 lug spindles will go on 71-87 truck spindles using all stock wheel bearings for those years. We carry stock both the 5 lug & 6 lug rotors. If you use the 73 up spindle be aware that there were 2 rotor thickness's used 1" and 1 1/4", the 6 lug rotors only work on spindles that were for 1 1/4" thick rotors.
You can find our rotors here
http://www.gmcpauls.com/Brakes&Steering.htm
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