tonight and tomorrow I'm replacing the front u-joints and wheel bearings. The u-joints are still a PITA, but the bearings coming out easy makes the job so much easier.
What were the symptoms that led you to deciding that the front u-joints need to be changed? I hope I'm understanding "front u-joints" to be the axel shaft u-joints? It would appear that is correct as you are doing the wheel bearings too.
The reason I ask is I've been fighting this front vibration "forever". It's a slow starting vibration that increases in frequency as speed increases, it almost seems to go away around 55 - 60 but worsens after 68 or so - not a death wobble, more like an "out of balance deal". It's not a loose shock - new bilstiens all the way around, new track bar, rod end links, drag bar links, (both the rod and drag links had lots of play) steering box is properly adjusted, pitman arm is fine, found slack in r/upper ball joint - replaced top & bottom, left side tight, bearings have lesst than 0. 0001 play - both sides. I've checked the control arm bushings and w/150k + they're not too bad, I plan on going with a good aftermarket set of uppers and lowers - eventually. So you can see I've run the gambit pretty much and still have the wonderful world of vibrations. The wheels are newer (bought new a few years ago), but the truck did this with the stock chrome wheels, tires - no band separations and on the balance machine the wheel/tire assy spind true. First I tried, road force balancing, then dyna beads, then centramatics, then removed the dyna beads (leving the centramatics on) then speed balancing and leaving the centramatics on. There's still a low speed (kind of a hopping sensation). I had a friend of mine get next to me at speed and watch the front wheels both the right and left side appear to be hopping like an out of balance wheel?

#@$%!
So the only thing I think that could be an issues is either a bend axel shaft or bad axel shat u-joints - Oh buy the way I've alread removed the front drive shaft for plenty of miles and still the same thing. It's gotta be somthing in the rotating mass - wheel bearings tight, only things left are bent shaft or bad u-joint??? what do you think??? and why did you decide to change axel u-joints??? What was/is your's doing that you are changing the u-joints and wheel bearings??? Thanks,
Joe Mc