Tom,
You can use the 44C, as I have a 44C I use with my 1450. However, the top center drive pulley, or like I did, the entire center spindle will need swapped to the one that is on the original 44 inch deck, which should be a 44A. Also, you will need to move the left side (side away from the discharge chute) front lifting eye to the outside hole above the front roller (if it has both holes).
I had the original 44A that came with my 1450 the previous owner must have used as a battering ram, because the entire front side of the deck was pushed back. I had bought a 782 with a blown engine to get the tiller, deck and use the tractor for parts. The 44C that came with the 782 was in much better shape than my 44A. So about 10 minutes to swap the center spindle and move the lift eye, all was good.
If your center spindle in the 44A has issues, you can remove the pulleys from the spindles and swap just the pulleys. For me the spindle was in good shape, so I took the easier way out.......
Unfortunately, you can't use the 44C as-is, because the main difference between the 44A and 44C deck is the size of the center top drive pulley (the one that sticks out above the belt cover when it's installed). All IH Cub Cadets from the 1961 Originals through the last 1979 Quietline used an ~1/2 inch drive belt from the PTO pulley to the attachments. When the 82 Series (Red) tractor were released in 1980, IH changed the PTO drive belt size to an ~5/8 inch belt. This is what the A and C designate on the decks. So, if you just run the deck as-is, after you move the lift eye, the belt will slip under a heavy load, because one end of the belt will not fit the pulley, If you use the 1/2 belt, the deck will slip, if you use the 5/8 belt, it won't fit in the PTO and slip. I had this issue with my tiller, it had a 5/8 pulley on the gear box, and the 1/2 belt would slop when you put the tiller in the ground.... and, before your ask, no you can't move a PTO pulley from an 82 series over to your tractor.......