I just put some wider rims and tires on my 99 f350 4x4 srw, in a tight turn the tires rub, so I am going to buy some spacers/adapters, will these create an unsafe towing situation, or will my truck still have the same tow capacity?

Will have no effect except to stop the rubbing. 1" spacers should be enough.

Excellent, thanks for the info buddy.

Yw. Make sure you check on those spacers though, you may need wider ones.