You have a laundry list of issues and it sounds like you need to start with the obvious basics first and then pull your heads and see what your bottom end has in it.
If it is a 78 bottom with dish pistons then someone attempted a compression upgrade with the smaller chamber earlier dove c's
If they are flat tops its likely total engine swap.
As for everything else you need to go through all the basics first.
What's radiator condition fan clutch fuel tank timing chain etc.
This won't be a couple paragraph fix it's going to take a step by step process of elimination addressing fuel system, cooling system basic timing etc first and then you can get into the meat and potatoes of the cam, bottom end, and cylinder heads.