Anybody tell me the best place to get parts to convert front spindle and drum brakes to the big bolt pattern 5 on 4 1/2 and disc brakes

 

I don't know where you are, near a large city? Search Craigslist for a junker 73 A body will have disk brakes, you'll need the upper A arms, ball joints, spindles, etc. Pull any brake valves you see down below the master on the frame, with the lines (for the nuts) as well as the master.

Otherwise, junk yard?

 

1976 to 1989 F and M bodies are another source. If you got 900.00 bucks you can get all new from SSBC.