One thought I did have on this matter.. .while 30' up on a ladder in 28 degree temps this AM LOL..... I don't know of a reason for the Mopar engineers TO keep the same bobweight into the Magnum... but on the other hand, there might be production reasons to do so. (Like not changing tooling setups....)
BTW, I just corrected my ring weight numbers for the 273 2 BBL...my original number was a tad heavy. Now bobweight is 2163 grams (measured) vs 2161 gr for the 5.2....
Can't see why not..... if it is a crank that does the same job, has the same oiling, same dimensions, etc..... what is the detriment to doing so??? Would anyone really object to the news that we put a 273 cast crank in my son's 340? Balanced up easily (by design), has the strength to do the HP/torque we wanted.... My Mitsubishi Starion 2.6L turbo rally engine has VW flat top forged pistons in it... running 1.75 HP per CI.
It would be interesting to see what can be dug up on factory balance tolerances....