Not sure why the real concern about the 400 and its model year? Reason is that they were ALL 8.2 CR, had the later (slightly different from prior 383s) cam, and generally considered an "emissions motor" (and therefore "not worth messing with" by many). The 400 is also generally limited to a .030" overbore, due to the later thin-wall castings, which generally means ONE overbore with a rebuild operation. From a worn factory bore, it usually takes that much of a cut to get to "clean metal" for a round bore diameter, by observation.
As for the "stroker" orientation, cut the mains on a 440 crank down tro 383//400 size and "instant stroker" to about 452cid. Reuse the factory pistons and rods, but rebalance them?
The bore on the 400 is larger than that of the 440, but with the shorter "383-length" stroke, which is where the additional 12cid comes from. 12 cid that could probably be compensated for by a slight bit more cam duration/lift without all of the time/./expense of the stroker situation, it seems to me. BUT I know that some people like these things. Is a neat way to get more inches from a low-block B engine, though, without having to change the external things like intake manifolds and such.
With the longer stroke, some of the 383/400s ability to "zing" might be diminished due to the lower rod ratio. As the Chrysler 383/400 shares the same rod ratio as the 302 Chevy small block, which was noted for its higher-rpm capabilities, IF that matters. Just as the 383 shares the same bore/stroke ratio with the 302, also. NOT a bad deal, but just takes a little more finesse to make the motors work as well as they can, by observation.
So the B motor is more "rpm oriented" as the RB (longer stroke) is more "torque oriented", by comparison, in the basic design (rod ratio).
End result, the 400 can have the same performance capabilities as a 383 did. The 4bbl HO engines still had the windage trays and other internal upgrades as the 383//335 motor had, all the way to the end of production (according to the Dealer Order Guide), but with the 8.2CR for emissions purposes. 400 automatics should have had cast cranks, although the 400HO 4-speed cars had steel cranks. NOT a big deal for a reasonably stock power Chrysler engine, or even one with some performance items either. Main difference is the balancer/flywheel/torque converter matching of this situation, just as on other brands of engines where some used a cast crank and others used a steel crank.
So, build your 400 with some "quench dome" pistons to get the CR back up into the middle 9-range. Use a 383 RR spec cam, or a little better. Clean up the head ports (stock valve sizes are fine), and enjoy!
CBODY67