As for the U-joints, the best way is to get under your truck and wiggle each d-shaft at the joints and check for any movement at all, if they look like they are moving at all when you wiggle, then you have some U-joint wear as there shouldn't be any play.

As for the 'drive-awa shudder', you got my attention. When I pull away at a moderate pace, I don't get the sgudder, BUT, when I HONK on it, I get a shudder for about 2 seconds, I never thought to check the carrier bearing. This leads to my question, do you have a lift kit? I have an 8" lift with the drive-line geometry in good line, my next question, does the 'rubber' lining of the carrier bearing housing wear and create too much play???

Cheers!