[mcampbell]

Big O Tires has dinged me a couple of times so I will cheerfully use their name here. First time I learned to never go back. The second time I bought a 99 Suburban with Big O tires already installed. I took it in for balance every month or two because it had vibrations in the front tires. Every time they rebalanced the speeds changed but they could never remove it completely. Sometimes the vibration was from 65 to 72 mph and after a balance it would be from 58-67 mph etc. Stock Suburban I had changed the cv shafts, rebalanced the drivelines etc.
After 6 months of this I asked,"At what point do you decide these tires are junk and give me a warranty?" I got the ol dance about how they had changed computers and it did not show me in the database and they would not help because this was my first complaint. I have since had Michelins, BF Goodrich, and Toyo's on the truck. (213,000 mi)with absolutly no vibration at different freeway speeds.
I would borrow tires and rims from one of your buddies and give them a test drive. You might also rotate tires and see if it changes. I would personally recommend as I already do to my friends to not patronize the Big Zero( but just not going there will likely not fix your vibration issue.) Good Luck.