Pale Roader, have you seen a DOHC Mod motor out of the car? It's wider than it is long.

The 4.7 is a small, lightweight engine and would indeed make a fine A-body motor, or probably fit pretty well in a '30s or '40s Plymouth or Dodge. I'd say you either need to start with the entire stock wiring system and fuel tank, or else plan a different transmission and Megasquirt. That's just a guess.
Stock cams are assembled out of pieces and supply oil to the rockers. I don't know about upgrades.

R.