irritating vibration

I have new tires on my 1999 K1500 Suburban. They have been balanced three times and I still have vibration between 60-72 mph.
before I purchased the new tires there was no vibration.
I have replaced the u-joints.
What's the solution?

Did the shop use road force variation balance? That will pick up internal defects in the tires a standard balance will not detect. Double check with the shop and if they don't know what that is, go somewhere where they do.

Ya try another shop or you can dump some anti freeze in the wheel. This will fill in the uneven spots while the tire is rotating. Have friends that do it with big tires.

What kind of "big tires" do they do that on??

I've got 44" TSL's on one truck and 60" tractor tires on another. I wouldn't dream of putting any liquids in there. The only reason they ride rough is because they start to settle and turn "square" easily.

But ya, do what Grant said!!

They happened to be on a Peterbuilt truck. Fronts. Had a up down bumping. Too many Arkansas I 40 pot holes!!!

tires

You don't have to put liquids in tires!!!! This will cause more problems in the end. If these are an oversized tire, then all they are doing is settling when parked as stated before.. Chec the tire pressure, they are suppose to be a lot higher than regular tires. Example most oversized truck tires will run around 65p.s.i.