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

IMHO, a waste of money on a well seasoned block that measures out OK.
But it your money to spend to keep from being called a cheapskate.

Some like Budweiser Beer. I would not use it to wash mud off my boots. Basically "Opinions are like ......" My opinions are not always right but maybe some of yours are not too.

Your “well seasoned” block won’t have straight bores, decks or main line. I outlined what I consider to be the bare minimum for machine work to do a rebuild on a core. As RRR pointed out, the prices weren’t even unrealistic or unreasonable. You can do it cheaper but what’s the gain except you have a few more dollars in your pocket? And as the numbers point out, and as I said from the beginning the 3k rebuild number is unrealistic and unreasonable. Doesn’t matter what engine you start with.