Not assuming. I've been following his thread on Moparts since the beginning. He is having everything made in the US. No Chinese junk. Is he in over his head? Probably. But read the update on Moparts. He has piles of parts to assemble but had family issues.
As far as letting the 340 sing, go for it. I'm too old for that. I want an overdrive. It would make my car truly liveable on the highway while allowing me to put in the 3.91 or 4.10 gears that it needs.