Ok so it is done, here are a few more observations for the record.

First something I didn't mention before; the bad u joint was actually on the rear shaft, and manifested itself through the steering wheel as a violent vibration so I thought it was the front. Not so.

Went with the flange bolt to fix the spinning bolt l, ground off a little on one side and worked a treat, as kennith would say (wrong forum, sorry). There is a giant circlip holding the bolts in the output flange. I hate circlips. Did I mention that I hate circlips. What a pain that was.

Anyhoo, I looked at the driveshafts on the other two cars in my driveway (volvos) and the universals were lined up so I put the rear shaft in an aligned orientation and it works great, no vibes at all so that's that.

Last mention goes to removing the old universals. Three of the eight caps in the rear were so bound up that I had to shatter them with a drift and break them out piece by piece. I was truly amazed that I didn't break the ears off the yokes in the process.

All in all a really ugly job in total, had I had the cashola I would have gladly ponied up the bucks to have someone else do it.

On a separate but related note, the harbor freight 20 ton press I have is going up for sale cheap. I tried to press the caps out with it to almost disastrous results. That thing loads up like a giant spring under even the smallest pressure and leads to dangerous events. I have a rather large bruise on my chest from a socket that shot out under load and am thankful to have my face still intact. Yeesh. Back to my brothers shop and his 120 ton nonspitting real press for all future needs.

All in all, very happy with the outcome, though.

 

Sounds good. Glad the ground flange bolt worked.
So do you think the issue with the press is something specific to the HF tool? Whether it's a 12 ton or 120 ton I would think the press would load the same way.

 

For comparison, remove the circlip then refit the flange and try to refit the propshft. You'll soon discover how much you love circlips. At least in that application.