Let me add this....having rebuilt engines and transmissions and rear-ends and all of that, learned from round track days, the info needed on this torque tube, I got straight from Stovebolt.com.
I remember when I got this truck home back in January, I called the guy who built our race engines for years. He's forgotten more than most will know in a lifetime. I was telling him about this drive shaft design, and how I had never seen anything like this. He busted out laughing, and then he explained what it was.
He also said to research it, cause he was sure they made some kind of replacement seal/bushing for it.
So what did I do? Went to Stovebolt.com, and searched. And now I know.
Mike