Sure is. Thats why itis a problem. Going out and building something like this is counter productive.
SUre we are only talking about a 20% decrease in strength, but you and I seem to be tearing up some Dana 60 parts and more strength is something that we are after.
Since the low pinion stuff is so much less exensive, buying one of these is probably much easier than building one.
I could not imagine welding something like this without some sort of fixture.
Dollar for dollar the correct axle is not all that expensive.

 

They address that point Ed and say it does not seem to be a problem, however he never finished the project and hasn't put it under a rig yet so we will never know how well it performs (until he does of course). It's good to see people thinking outside of the box, but I think I might be with you on it not being worth it - d60s can be found for 800 pretty easily and under that if you do some searching, and it looks like he has close to 600 plus his time into it already.