do cyclinders need to actually be perfectly smooth? so long as they are not damaged near the surface where compression takes place. they should work fine. though you do need that crosshatch on the walls. and there is no retail honing bit which properly does this. not the way ford does it. but.... probably get by on just a regular crosshatch.
a 300$ rebuild kit should do it, if you polish the crank journals yourself, and MAYBE take it in to get it balanced on an actual machine (should cost 50$)
heads can be resurfaced by hand also, all you need is a perfectly flat bar
valves can be done by hand too, with a rotary tool, or something similar
Some of these things it just doesn't work to take shortcuts with. The most important part is for the cylinder to be round. So if it's not you have to bore it. I have done plenty of engines that were just freshening them up and ran a home or a ball hone in them for 20 or 30 seconds installed new rings and I've never had any problems with them sealing or having proper compression.
I was building all these in the day where Molly Rings were all the rage. Then later just a top Molly ring was common. Everyone has their opinion and often people said cast rings are better because Molly had a hard time ceiling but I basically just use TRW, sealed power, or better I think Hastings rings a bell, and never had any problems.
If the cylinder is perfectly round and you give it a decent hone then the Rings will seat but no matter how good the Finish is on the cylinder if it's not perfectly round they will not seal. I had a block messed up one time because the guy had a boring machine mess up and had to switch machines so two of my cylinders were way out of round.
There is no way you should consider doing any Milling two heads by yourself.
If they are aluminum you could clean them up a little bit but you're not going to take care of any warping issues at all.
I used coarse sandpaper on a steel plate and I mean like three pieces of sandpaper taped down to it on a Suzuki Samurai aluminum head one time when it blew a head gasket and sanded and sanded probably still didn't take . 008-.010 off.
Clean them up is one thing but mailing one that's warped you need to go ahead and pay the money and have it a surface cut.
Most of the time valves are just fine so if you want to slap them in to make them feel a little bit better you're not hurting anything but it's probably more a waste of time and everything else.
It's the guides that are often way loose and the seals need replaced so they won't blow so much oil. It's also best just to have the heads done at a machine shop.
The cost do add up but the cost involved with getting a motor Replaced is all about paying big money for the reman engine and the labor to install. When you're doing a labor yourself and not buying a package engine you can do it much cheaper.
Of course if it's a small block Chevy they was always the cheapest one to do.
The magazines always had those cheap rebuild kit but I never bothered with them. Too many cheap gaskets and stuff like that. Cheap parts.
I freshened up a 350 truck motor probably about a 77 model year back in 2000 for a fiberglass body jeep that I purchased without an engine.
Reused the factory pistons just honed out the block with a drill and put new rings and it. I had a buddy hot tank the old block and put new cam bearings in it that wasn't too much money.
New oil pump, new rings, new Main and rod bearings, the cam bearings, painted the intake aluminum to look like an aluminum one, painted the block bright red, my buddy milled the heads and did a complete valve job for a little over a hundred bucks, splurged and put an Edelbrock Chrome kit and huge Moroso Chrome air filter on it, new distributor cap and rotor spark plugs and pretty blue spark plug wires oh, I think I had to put the terminals on myself from a set from Pep Boys so I can get the color I wanted... basic gaskets or I might have got one of the head sets, I always use Fel-Pro.
And I put a 6999 crane cam 327 350 horsepower in it or whatever that cheap Saturday night special one was.
I paid a hundred bucks for the engine sitting on guys garage floor few miles away and with all the parts and everything had a total of 620 in the complete project.
Didn't have a cherry picker at the time but I didn't have to rent one since it was a Jeep. Fiberglass body so the fenders unbolt with three or four bolts. All it was there once you take the radiator out were two frame rails about knee level high. We just wrapped one of those yellow Towing straps around the engine and stuck a long piece of galvanized inch and a half pipe through it and we lifted it up and walked it back on to the cradle.
I did had about a 20% discount on all of those parts so that helped some.