1973 Other Chevrolet Models Starter

Engine Mechanical problem
1973 Other Chevrolet Models V8 Two Wheel Drive Automatic 472k miles

I have a 1973 chevy c-20 P/U. I have replaced the starter about 6 times now. I have replaced the starter bolts and the flywheel twice. I have even gotten a high torque starter and put that on. It lasted about the same time as all the rest. This is the last time I ever want to deal with this. I need help. As much help or any suggestion as to what it could be. Thank you everyone for your help.