Don't get it right, just get it running. 85 318 roller

Not like anyone cares but I would clean it up take measurenmehts and figure out if you can get away with dingle ball honing it.
Then Id disassemble the heads and see how much play is in the guides, at the least reseal and lap valves.
According to what I find I then start making a list of parts. Remember overhaul ,rebuild, blueprint and balance...its 3 levels of operation each level costs more $$$
I fit is a race engine yes you go Blueprint and balance but its the guys who say you have to do this with everything that lead people astray. You dont need to get microscopic on a 80s 5.2 318 build. check at home with feeler guages for taper and out of round and do the math youll know if it needs a overbore or a rering etc. do the research work do the measurements do the math. Spend your own $$ on what you want and what you need. I always see an overbore as why sharpen the pencil when the point is still good leave some meat there for later.
A machine shop will machine your engine on demand and charge you for it that's what they are in business for.