hi, to approach this from another angle...I had a spare , worn out, steering box from an 82 Eagle. My 77 Hornet needed a new one. I had the 82 Eagle gearbox rebuilt, and put it in the Hornet. Night and day difference. the old 77 was a 17: 1 ratio, and worn out. the 82 Eagle is 14:1 ratio, and feels MUCH better in the Hornet. All the old slop is gone. BTW, afaik, the Eagles came with either the 14:1 single ratio, or a 16/13:1 variable ratio. Also, I wouldn't rebuild a gearbox myself, unless one is a pro. I used a place called PowerSteering.com, in Nixa, Missouri, not cheap, but they do an excellent job.
A squealing belt may be just the belt, or your pump may need rebuilding, The pumps I rebuild myself, a kit is only about $15. anywhere. The only PITA in this job is removing and reinstalling the pulley, for which you need a pulley removal tool kit, cheap a Harbor Freight, or rent locally. good luck, gz
Btw, if your pump has never been apart, there is a very good chance it is full of all kinds of crud. I couldn't believe how much junk was in mine. If you don't rebuild, at least flush the system.