carb replacement suggestions
lf built and set up properly, the thermoquads can be good carbs, there is a good following for them here.
I would run a thermoquad or Holley spreadbore over a quadrajet.
Try looking into a Holley 6711. It's a 650 mechanical secondary spread bore and is supposed to replace the thermoquad. It's pretty big for a 650. However, it can't be converted to electric choke, only manual....