Today, dollar for dollar, is the 318 faster than the 340 ???

No sense measuring anything if you are just going to run it. When the main bearing clearance is .0022 plus a couple of tenths minus zero and you have a journal with .0003 taper it’s already out of spec. I won’t run that. If you measure the bores and it has .0010 taper it will take another thou and a half to get it straight so that means the bore will be too big for the pistons. You can measure all you want but if you are using the FSM tolerances they are so sloppy it’s not worth measuring. Maybe you should go hang out with some real engine builders and see what they do. Unless you don’t want to learn little buddy.
Hmm so you just going to throw money at it without even measuring.. makes sense that you would do that. As it's pretty clear already that you have no idea as to why machine work can't and won't fix core shift. Then you try and bandage it up by throwing more money at a junk block. The friend I had probably would have scrapped your high dollar junk in the salvage yard. So go study core shift. And why it can't be fixed. And all of the areas that it effects and also why after spinning a main that the block is now crooked. Don't be cheap and lazy little buddy. Have faith you will get there. Just takes time