Projects flipping a 1983 C-10 for a late 40's- mid 50's mopar

I would like to get a flat head 6 mopar. I guess that I miss the kind of cars that my grand pa had when I was a kid. Green 49 Plymouth fastback,cream 4 dr 48 Plymouth and a 52 Desoto fluid drive 4 dr gray. What kind of things do I need to look out for when looking at these cars? Fluid drive good or pass, motors to avoid,12 volt conv? I have time to look while I am finishing the body work on the truck.