Sorry but I think this idea is a little flawed. First of all, it's the internet, people just say whatever **** comes to their mind (fingers?) without really thinking it through. Maybe they just read a line or two of someone's post and type out "get a 340" as the automatic reply. Gotta wade through the detritus just like with everything else.
I think most guys here (who are old enough) know the reality of 2021 is different than the reality of 2001, let alone 1981, there's just not that many good 340 blocks around to build anymore. As we all know, 340s were produced for what, 6 model years? Plus the cars it came in were comparatively low production vehicles because 340 was the premium small block engine. Even the 360 4bbl cars never held the same cache as the high-winding 340s.
Chrysler's meat'n'potatoes was 318-equipped basic transportation cars, fleet vehicles and trucks. Aunt Ethel could probably gave a rat's *** about a 340 Duster but she sure loved putting her Sherwood green 318 Scamp to chruch every Sunday. Maybe she even thought it was peppy!
Then think about how many kids in the '70s and '80s blew 340s up or even just tossed them in the dumpster when they were done with 'em. If they had the foresight to know the supply of blocks would be non-existent 30-40 years later they may have thought twice. They didn't though because they had fun while it lasted and moved on to the next thing.
So here we are now debating whether lame-*** 318s are going to be "faster" than a 340 because you can't find any good, cheap blocks anymore. Does that make sense? No. But Guys on the internet still say to build a 340 which for whatever reason ruffles some feathers.
318s suck, I would never advise anyone to waste money trying to wring any amount of power out of one, it's not worth the expense. It's like the loony Slant 6 guys, these types have a Napoleon complex. Get over it, buy a 360, stroke it to 422 and be happy. Life is too short to waste money trying to prove a point that no one cares about. If guys want to prove they can do it then go for it, make us all believers but stop making weird arguments trying to convince people otherwise.