The car only has 1200 miles on it now.
About 3-4 weeks ago I had removed the shaft for re-balancing,
at that time I found that the NEW bearing and rubber had pulled from the carrier. That would explain that "clunkclunkclunkclunk" on launch, but it did not have the (i dunno--shudder, buzz, vibration, harmonics

) any worse then, than it does now, (rebalance-new bearings).
Could very well be the differential---that is the only component that has not been replaced with a new one. It has some tall gearing as it came from a 6/pg car. I'm just saving to get another diff. rebuilt with a posi, hoping I can get 3:36 or 3:08 gears----454 need MPG
I think the reason the bearing pulled out was that during assembly of the frame, there was no weight on the suspension (body off--frame replaced). As the body was installed and the rest of the weight adding installs, the driveshaft pulls away from the tranny close to 1-1/2" .
And as GM engineers had a great brain fart, they did not include a slip yoke AFTER the carrier, where common sense and most normal people would have put one. Have no idea why they put a slip on the front shaft, does not go up or down, and really shouldn't have to go in and out.
Purchasing a rear shaft with a slip yoke is on my agenda.
Hijack alert

sorry
Bryan
PS---Poncho----I would be a lot better off if I had found this little community about 2 years ago---not AFTER I registered the car last June