BTW
I have had numerous stock 340s, some nearly new, and with gear ratios from 3.23 to 4.10. Once you get them into a roadgear of say 3.91 or so, they were all done pulling in the midrange. I could always feel when mine started to nose over. On the street, with traction, you gotta gear them just right to survive the 1-2 shift, and if you don't, they will just lay down. Which is real embarrassing when a correctly geared 318 car comes along and blows you off.
Yeah sure they pull at 5000, but with a roadgear of 3.91, that works out to around 100 mph, which, last time I checked, is not street territory.
BTW-2
the hi-compression 318's were rated 320 ftlbs at 2400, whereas
the hi-compression 340's were rated 320 but @3400.
What any of them actually made, is anyone's guess, cuz everybody seemed to be lying about those kinds of things back in the day.
Jus saying