Converting from 318 to 360
You can get a 22" Heavy Duty 318 w/AC / 340/360 Radiator from Advance Auto or Autozone for under $200. Order one for a 71 Dart. I am using one of these on a hot 360 and it cools fine.
This will put the lower radiator hose on the passenger side. Your 79 360 should have the front cover and water pump on the passenger side.