Took the ds to the shop mentioned above and they said it really didn't need a new slip spline. They did find that it was slightly bent which the other shop did not find. So they straightened it and rebalanced it for about $120.

I put it back on last week and no vibrations at all since then even at highway speeds. So I at least now have a driveline shop that I can trust and knows what the hell they are doing.

Now just have to play around with my caster a bit to find the sweet spot.

 

Buy New so then you wont have to upgrade it later.