Generally speaking- if you feel the vibration in your seat, the cause is in the rear. If you feel the problem in the steering wheel, look in the front. If it was happening before your new wheel/tires it rules them out, UNLESS... you had a bad original tire or out of balance, and now one or more of your new tires are out of balance, or is just a bad tire. I had a new set of 4 tires installed years ago and 2 of them were bad, which I felt as soon as I left the parking lot. Also, an indicator of poor balancing is when you see excessive weights on a rim, or a weight in one spot and another about 170 degress across. Someone didnt put the first weight in the right spot on the rim. New tires should also be road force balanced which includes tire/wheel matching to reduce the amount of weight needed. More expensive but worth it. Especially important on larger tires like a truck. Last, if you have exhausted all tire/rim problems, check the driveshaft for weights at either or both ends. A weight may have come off, as indicated by a clean spot. Keep us posted, so we all learn. Good luck.