+1, check the bore first before just punching out the holes. I try not boring or any additional machining at all unless a VERY good reason to do so. If the cylinders are rusty, might just bore it anyways.
If this is a simple rebuild with under 85K miles, everything is tight just only "old", not a knocker or all sludged up inside, likely you can get away with a good honing of the piston bores, new cam bearings, new rings, rod & main bearings, timing set, gaskets, oil pump, pickup screen and maybe a cam & lifers (definitely cam & lifters if sludgey inside) Try if at all possible (pending accurate good results of measurements) to avoid all of the glamour of doing EVERYTHING. Just keep track of the "numbered", machined items (rod caps, main caps) and be sure they get back to the same places, facing the same direction as removed.
Strip down the block removing all freeze plugs, camshaft, crank, pistons, lifters down to a bare block. Send the bare block to be hot tanked at your machine shop. Be sure to have them brush out the oil galleries too (often people don't do this...not good
) Have them measure your bore and then get back to us or call a good builder with the results. Many machine shops are out to have you do EVERYTHING possible but often, if the above situations are true, those items are not needed. Don't over-do it. It's only "original" once. Plan on having the shop install your cam bearings. You usually should provide them a camshaft to help them. Your used one should be adequate. If you plan to reuse your old camshaft, maybe protect the lobes from "dinging" them by wrapping it up in rags. It is fragile.
You could send the heads in at the same time too (no rockers, but leave the valves in place) Be sure and hide a "punch mark" located in an unmachined area of the castings. Use this to ID your block & heads as "yours", hide this in a place that only you know where to look. Some places (shops) could be unscrupulous if you have anything of value...they could know somebody who needs "your" parts & habd you back somebody else's junk
There's so much more to write, but no more time right now. This is a good start.