CV Joint: variations & acceptable wear, Re using original CV joints Options

[Gearhead1432]

I'm in the process of rebuilding the axles in my 914. The two half shafts that came off the car have mixed CV joints, that is, two are VW and two are GKN. All have minimal wear on the outer and inner races. Unfortunately one of the VW joints has a crack in the cage.... so it's toast.

I also have two donor axles. All 4 joints are VW and still have the two piece boots as well.

Besides using my "best" judgment, at what level of wear should I reject a CV joint for further use? I have also noticed the GKN made joints are totally different than the original VW joints. The VW joints fit tighter on assembly. The balls fit securely in the cages as opposed to the GKN joints which fall apart on a whim. All four of the joints I inspected had roughly the same wear on them.

Also, are GKN CV joints still made in Germany? Do they still have the black oxide finish?

-Rob