Lower priced Power lok, sure grip units on Ebay.

Bottom line: It depends on the quality of the metallurgy, and the machining.
If the metal is good, and the machining is good, it's a great bargain. If it's not.... it's not. If the ring gear flange is perpendicular to the bearings surfaces, and the runout is within spec....... it sure might be worth a try.
And anybody that does stupid **** in the rain with a posi/suregrip/lsd by whatever name, IS stupid.