Its not just numbers matching ppl. There are armies of ppl who think there is some magic in 340s. Some mysterious power making something in the 340s. Baby Hemi, X heads are gold ect. Any other small blocks are sub standard in their eyes.
Forget about the open chamber heads, lack of quench, heavier pistons than a 440, short stroke, excessive cost of 340s ect. Those draw backs do not matter to that crowd. You wont be able to reason and talk any sense to them either. 340s rule, 340s are the best, 360s are inferior, 318s are boat anchors, 273s belong in dumpsters etc. And its a big crowd too. 340 mania, its a real thing.