You will create a 1979
I don't think the extra ballast in the 1980 vs the 1972 will "bend" anything, as I say, the 1979 O'DAY 22 was the short rig but with the keel/CB and 700# ballast instead of 600#. Your 1980 has 800# ballast, so you are looking at maybe 200# more ballast than the original 1972, in other words...about equal to one to one and 1/2 crewmembers. Should not be a problem! I would check the standing rigging from the 1972 mast, it may be near time to be replaced anyway, give Rudy at D&R a call, he can recommend replacements (he makes the rigging in house). My question though is whether the maststep on the 1972 is located the same place as on the 1980? I do know that the chainplates will have to be moved for the 1972 rig, they are farther aft on the 1980-83 rig. The boom is 9' on the 1980, 8' 6" on 1972.Sail Area (100% jib) for the 1972 was 190 sqft, 1980 was 198 sqft. but a larger genoa was added to many of the older (pre-1980) boats and that will increase the total sail area.My guess is that with decent sails (if the ones from the 1972 are original, they will need replacement!) your 1980 22 will be as fast or maybe, maybe slightly faster than a typical pre-1979 22, but at what cost?My advice, replace the 1980 mast with a new one the same length, I bet it will be less expensive in the long run. You may be able to just replace the extrusion, and reuse most of the hardware.