if you want it to be a reliable Highway driver I would approach it like this...
I would take a bore gauge and measure all the cylinders after I tore it apart to see how out of round and tapered they are only if I don't see a ginormous Ridge at the top already. If it's .0025+ out of round, id bore it and buy flat pistons for a 1971 318, or roughly ones with a 1.74 or 1.75 comp height, then id mill the block .020 because they are usually about .020 taller than listed..then check the head chamber volume/cc and mill the heads about .040 if they are bigger than 68cc. The head gasket will eat up .025 of what you.. mill therefore you'll only have about a .035 height change in intake manifold height which will bolt up fine. Have a good valve job done, no flash or ridge left underneath it in the bowl.
Then a small cam, 252 duration or something like that. Done.
The blueprinting machine work is most of a good engine. Know what you have.
It will run like the money/effort you put into it.
