Front drum HELP!!

I missed something. You upgraded from 9 inch to 10 inchers, same 5x4 pattern. This is a problem, how? Or are you wanting the 5x4.5 pattern. To get a 5x4.5, 10 inch drum you would need to get something off a B/E-body. Have you considered the std 5x4.5 disc brakes from any thus equipped post 73 A-body? Just swap in everything between the balljoints.