4th gear 2800--3K rpms

Hello Everyone

I just thought the least I can do is let you all know what happened.
You all are so helpful answering problems that have nothing to do with all of you yet when we get our shyt fixed we don't say anything?
Not right.

Ok I finally got the car to the driveshaft place and he said something to me that was kind of new (hell everything is new to me lol) after looking at the car he said that he removed the drive shaft and saw that the joints were not greased properly and that if I store the car for the winter (more than 6 months) I should grease them before I store them as they dry up and that could also cause the vibration. Damn simple greasing.
He did also balance the driveshaft as it seemed to be off somewhere on some weld from what I understood

When I took the car I asked him what if it's still vibrating do I come back (200 dollars later) he said no, there is nothing more I can do, it's another problem .
I'm thinking I just paid him 200 dollars to put some grease on the universal joints and driveshaft balanced.
Did either of those things need to have been done if it's still vibrating?

As soon as I left I went on the highway to get home, got into 4th gear and went 2500,2700 2900 and now I'm at 3 k and I'm not hearing, feeling anything,next thing you know I'm up to 5k and I'm coasting.
Finally, done. What a feeling. Been a yr since I felt this...
Thanks to all of you guys as well for your ideas, input and suggestions.

MAPS
Happy Ending !!