What engine would you build for a Ramcharger?

I was going off of the list you gave. Options were:
  1. '88 LA 318
  2. '76 LA 360
  3. 5.9 needing everything and sounding like this would be the least route you wanted to go.
Between the '88 318 and the '76 360, I think the '76 360 with stock cam will give you your best mileage in that Ramcharger

The 88 LA 318 is a roller motor. It would be my choice.