disk brake options (factory) 73 Scamp

I believe a Volare is an F/M/J body and many of the front end parts do swap. Tom Condran's "Performance Handling for Classic Mopars" book covers the options.

If you have small bolt pattern on your 73, it must be a slant six car. In that case, you could swap the 67-72 Kelsey-Hayes disc brakes and retain the small bolt pattern to match the rear. But it sounds like you want to convert all around.