Mopar made two different versions of the 440 "motorhome" motors, regular and the 440-3 H.D. version which has the extra cooling holes already mentioned. The first year (1973)mopar used the 440 motor home motors usally had the bigger, thicker, six pack rods, and forged steel crankshafts I'm not sure which year had those rods and exactly which year they switched away from then to the standard type 440 rods found in the later years
The later years had the external balancer and matching weighted converters
Before deciding to use any old motor parts have them thoroughly examined by a good competent machine for cracks, wear and other things like a good sonic test to see how far you can safely bore the blocks