I think my oil plug is stripped out on my 90 f350. It won't get tight, but no oil leaks out. What is the best fix for this problem? Thanks

 

The best fix is a new oil pan. Also make sure the pan threads are stripped and not the plug.
If a new oil pan is not in your budget or skill, you might get an oversized oil plug. One type I'm thinking of has a plug in a plug type arrangement. You simply screw in one plug that stays in permanently and there is a smaller plug in the larger one that you take out for oil changes. I've seen these at NAPA.

 

The treads on the plug look pretty smooth. I guess I should try a new plug first?

 

Try a fumoto valve never have to un-screw a plug again.works great.