A stainless Blackhawk in 45LC and a SuperBlackhawk in 44Mag (5.5" or less barrel) are damn near the same gun in every respect - heft, strength, weight, etc. Only the hammer would be a visual clue as to the difference and that's an easy swap.
Blue Blackhawks usually had the lighter aluminum grip giving them a real difference in recoil control. But again, that can be swapped too. The core frame (and basic strength) is identical with all post-1973 Blackhawks/Supers and "Old Vaqueros". I tend to call this the "44Magnum-class frame".
WITH ONE EXCEPTION: the 50th Anniversary Blackhawk 357 is built on the same "mid frame" as the New Vaquero. I sometimes call this the "357 frame" as that was the first caliber that frame size was chambered in. When set up in 45LC, either a NewVaq or a modified 50th 357, you can't run the 45LC+P mega-loads.