Advice needed...

I-would-not-put-the-340-into-the-truck-at-3.315-stroke
I-would-gladly-sacrifice-some-torque-in-the-Dart.One-issue-I-see,-is-that-with-a-larger-cam,the-rpm-of--peak-power-rises-about-200-rpm-per-cam-size.And-that-then-puts-the-mph-up-higher-as-well. So-yes-you-have-more-power,but-you-have-to-drive-faster-to-get-it,whereas-gears-reduce-the-mph-to-get-the-power,and-multiply-the-torque-simultaneously.
My-favorite-combo-has-always-been-a-223*cam-in-my-Eddie-headed-11/1-367,68-Cuda-@3650#.It-had-the-strongest-low-rpm-of-the-three-cams-that-my-engine-has-seen.And-that-is-what-made-it-so-fun.
So-yeah-I-see-the-torquey-360-in-the-truck-and-the-340-in-the-Dart.However,in-the-340-I-would-either-go-easy-on-the-cam,or,I-would-increase-the-cylinder-pressure-a bit-to-keep-the-low-rpm-power-up. Or-you-could-fall-back-on-a-higher-stall.
One-thing-I-see-being helpful,-is-a-solid-lifter-cam-of-about-230*.050,-yet-only-260/268-advertised.This-might-work-well-with-9.8Scr-or-more,-making-power-through out the rpm band.
A stick car has a bit of a handicap in first gear at low rpm because the tires are married to the crank, without benefit of the fluid coupling or torque multiplication from the TC. So adequate cylinder pressure is kindof a big deal.
Alternatively, the 3.09 low box can more that make up for a lazy engine........until you get to second gear. 30mph with 3.55s and 26s will be about 2650 rpm in second. A 340 with a 284FTH, at 2650 is gonna be a bit lazy until you get her up to 10.0Scr or better, 10.6 being about optimum.
BUT If you can't get traction,then; big-power, or mega-torque-multiplication is kindof pointless.
At one time I had the bright idea of putting 4.88s behind my A833OD, and GVOD. This gave me ratios of 15.08-11.76-8.15-6.36-4.88-3.81-2.70 and,with somewhere near 430 ftlbs, this would get me up to 6600ftlbs on the start line! and I was ready to carry the front wheels like a SS-hemi of yesteryear. Yeah that was the dream. The reality was that the 325/50-15 BFG-DRs could barely hold 1500ftlbs, so I had to baby it out in 15.08, and immediately hit the splitter for the 11.76 ratio,then gently feed it power, and grab second early; what a stupid idea,I thought.
I pulled those 4.88s out ASAP!
And the trans was the next to go.
The current combo has just up to 4700ftlbs available on the start-line, and it makes a smoking hot streeter!
Happy HotRodding