I had to the same problem on my truck with the coopers at discount tire. I took it to Goodyear and they were worse. They told me that they seem out of balance because the are new and since there isn't any grooves on them yet they go everywhere and vibrate. They had well over 6 oz on the rear only. I went back to discount and they swapped the coopers out for Nittos and all 4 have a little over 1 ounce or less. Smooth no vibrations on the new tires.
Anyway, I won't be going back to Goodyear.
Anyway, I won't be going back to Goodyear.