Help! from one ton guys!

[Big Block]

I bought a 1972 Chevy C/30 one ton dump truck and I need front rotors. The aftermarket rotors are 12.5 and rub on the dust sheild bolts on the inside of rotor. The original are 12 3/8 dia.. Everything that I can find has a taller hub. Aftermarket are 7 11/16 from rotor to top of hub. The originals are only 7 1/2 to 7 3/4. Can't tell for sure they are wore out and not much left. But they are not 7 11/16. I'm going nuts, GM doesn't make them any more. I'm sure they only fit 71 and 72 body. The parts books say they will fit later trucks but I know they dont' fit mine. I have 16" wheels. I bought new wheels and tires and am removing split rims. I bought longer studs to put in rotors but the rotors are junk. The front max weight is 7200 and the rear is 11000lbs. Help any one run into this problem. Thanks PS. I'm checking with local junk yards.