High Speed Vibration after 5100/TSB Rear Install

Ok i've searched for hours and cant figure out what this could exactly be. I think I might need a new balance and hubcentric rings but I would like to see what everyone has to say first.

I have a 2010 Sport DC. I had the dealer do the rear TSB done along with 5100's all around set at 1.75" up front. At this time the alignment was done for the stock setup, 265/65 tires. I then had 17" xd hoss rims installed with 265/70 Nitto Terra grappler tires the next week. I have a vibration from 70-80 mph. The steering wheel does not shake but you can feel it in the drivers seat and visibly see the passengers seat shaking. The steering also feels loose and it might be me going crazy but a slight pull to the right. The hub on the XD rims is 108 and I asked the tire shop if I needed the hubcentric rings and he said no. From everything I read I think the hubcentric rings are necessary and possibly a high speed balance. I did not have a realignment done with the new tires so im not sure if this would help also. I just want to see what everyone thinks before I do all of this and it not fix the problem. Thanks in advance!