It seems to me that one would be better off looking for a Dana/Spicer axle as came in GMCs of the 60s and on. Or maybe a corporate 14-bolt. For one thing you are much more likely to find highway gearing. And for another, have you or anyone else on this thread gone looking for a pinion bearing for an Eaton HO52/72? The last price I saw was in the high hundreds of dollars and only one source. So I quit looking and got a boneyard HO52 axle out of a 67, 3/4 ton. 4.57 ratio. Suited my application just fine.
If you run it long enough it will need a pinion bearing and by then it will likely be unavailable. At 76, I don't have that worry but some younger guys might want to think about parts availability.
