1997 Dodge Avenger Vibration problem @ around 68 mph

Hello there. I have a 1997 Dodge Avenger that I just recently put new tires on. They are 215/50/17 Uniroyal Tigerpaws, which replaced the Michelin Pilots that had been on the vehicle.

Since then, I've had a vibration problem. The wheels have been balanced twice, the alignment done twice as I had to replace the front stuts. My mechanic also went through the front end to check if anything was needed, as I know these cars had a recall on them for balljoints and control arms.

He says everything looks good. Still. It vibrates. It was never like that prior to the tire change.

I plan on checking the balance once more, as I'm suspecting a tire issue at this point.

What would your opinion be?

Thankyou.

Jim