A 431 or a 451 is really (more or less) an "optimized" 440...a 440 in a lighter (both in terms of overall mass and especially bobweight) packaging. So any strong 440 RB combination will work just a little bit better in a B based low deck version.

No need to Reinvent the wheel, the 426-440 RB has been the Mainstay of Mopar Bracket racing for 50+ years and there's still a LOT more 440 based bracket cars out there laying it down every week-end. So IMO there's nothing "mystical" or "magical" about a B block or any combination you build from it, it's just a little bit 'better' version of what has always been a very good and strong Engine.

I built a 431 well over 25 years ago using an OEM 454 truck piston and bushed rods, semi "exotic" for it's time I guess. But we did it get them to "sucker bet" against my little 383 but it really didn't run much better than a 440 with the same CR and Cam. I always liked 451's but more for the smaller packaging in A bodies because even 30 pounds was an advantage over the nose in an already nose-heavy (compared to a 340 anyway) combo.

Today with stroker kits and especially the heads out today the low deck advantages (relative to the cost of doing a comparable, ie light piston 440) is significantly less than it used to be. Nothing against them at all, and I've built more than many people have...but for reasons I can no longer defend other than for sentimental preference. Today, to me they're absolutely PERFECT for Road Runners and Super Bees and the other perfectly good oem 383-400 based cars out there, I just wouldn't go out of my way to build one anymore if I already had a 440.

So for an 'Ultimate' combination....just look at what already works the way you want or need it with a 440.