I am having turbo issues with my 05 6.0.

While traveling down the road my boost will vary from a few lbs to 10+ lbs of boost at 60 mph. There is no specific rhyme or reason to it. I can stop at a stop sign and hammer it pretty hard it will pull stong and hold 25 ish lbs of boost. On occasion it will stick and overboost (get it shut down before 30 lbs or so) and I can hear whooshing (wastegate???)

I pulled the turbo and the ring was stuck, I free'd it up and it moves, it seems like it was stick a bit at the extreme ends of the travel. I was unsure how much to work on cleaning up the ring ect (maybe go to far). Do I take it out again and clean more. Also if i put a fairly heavy coat of anti seize will that cause issues?

The truck has 105k on it and gets driven very little (33K in 6 years) and has never been in a shop since I purchased it.

Any ideas???

Eman