the weather checking is definitely more pronounced this last year than when I put them on. If they werent sitting in a small tripod pile in my moms yard since they were replaced by my step dad on his old 2005 chevy truck a few years back, directly in the sun and weather, face up, fileld with water etc etc, Im sure they wouldnt be as bad. But considering they sat in the sun and froze a few times, etc, I commend them for still holding it together and thats after my winter using the plow and the truck definitely putting the weight on those front ones while the rear ones just did their normal duty. 2k on the rear + the trucks normal weight, with the nose of the truck favoring the front ones probably isnt that hard on a 10 ply tire pair on the rear lol. at low speed.
on the driveshaft thing, diameter, circumference, those both would work. Im just wanting to know the "large" ness of the driveshafts compared to mine. I can measure mine. If you have the diameter you can find the circumference with a simple equation and if you have the circumference.. well frankly you only really need one or the other. if you do that for at least the one you put on your truck(from CUCV) that would be appreciated. But if you also do your one you removed, I would appreciate that too.
I just dont know
what mine came off of technically, and the shear amount of trucks that were snipped up and parted and came through etc I dont know what it would be. I learned the np208 and cross member I have were probably, but this probably was not certain, out of two different vehicles, because my uncle says he was pretty sure the truck the np208 and sm465 came out of wasnt the same wheel base but he could remember if it was a short bed truck, possibly out of a GMC jimmy(which they had for a few years apparently) or if it all came in like a trade.. basically I could have a driveshaft that was *close enough* and if that is the case, I may just seek a CUCV one like you