vibration with new tires and rims

[koyahan]

I have a 2006 h3, I recently got 20" kmc rockstars with 33"x8.5 toyo MT's. I now have a "getty up vibration feel at around 55mph-70mph. The tires are balanced. Although the wheel isnt a hubsentric wheel they dont make a spacer to fit in it cause the fit is pretty tight but not quite. I was wondering if anyone else has had this problem and what they did to fix it. Also there is no shake or vibration in steering wheel.