That's crazy about the thick wall wrist pins! I don't recall any other engine with bs like that. On the plus side, I would think that a 273 crank in a 340 would require very little Mallory metal.
You could. I'm sure the racers have done just that. In a way, pretty smart of Mopar doing that. Just change the wrist pins, a machined part, and you don't need to make new forging dies for a different design crank.