Input for 340 upgrades

Gonna take a good bit to get a stock stroke 340 in the 10’s NA
I can tell you what would get it done, because i just lived this with a 360.
Minitubbed 69 Dart 3300 with driver
Stock 360, bottom end stock
Eddie heads, very, very little porting. Went 256 max@550
260/264 Howard flat tappet 565/565
Hp 950
Stock airgap
Dougs headers
4.10 gear with 28” 275 radials
8 inch convertor
727
This combination went 11.26 shifting at 6100 almost 119 mph.
If the heads were “ good” i have zero doubt it would have run 10’s.
I then swapped to a 904 and new vert, and missed the convertor enough to where it didnt pickup over the 727. Never took it out as car was consistent, left it alone

personally, i wouldn't waste the money on the TTI step headers. They arent THAT much better( if any better) especially on a stock stroke deal.
I plan to run those same Dougs headers on my 418 i will be running next spring. Same cam, same heads, but they will be “ good”
Same carb, will use a single plane intake. I am betting at least 10.70’s in good air, maybe better.
Your thoughts regards the vert and Rpm..... dont worry about it. Buy a good tranny cooler and forget about it.
You will never get a stock stroke smallblock to run without an 8 inch convertor. That and a camshaft and having those heads ported would go a LONG way towards reaching your goals.
Guys do the hotrod tour with big verts without issues. That is an old wives tale these days. Convertors have come a long ways