For sure, run it till it quits, it will probably last as long as you need it. Bottom line is; you have options galore if and when the time comes to replace. Especially if you are looking for a rear axle, they are everywhere. Fronts are a bit more dicey, you have a limited supply because not all trucks are 4x4 and you have more on them that can be junk, like ball joints and such. But I'm just pointing out the obvious now!
Also, welcome to the forum.
