hey guys. i got a 1994 ZJ Laredo V8 all time 4 wd. I have a 2 inch budget boost. Just the spacers. When I hit about 55-60 MPH I got a bad vibration going on... If i let off the gas it calms down a little bit, but it;s still there. i am supposed to be taking this thing on about a 600 mile drive next week, and most of it will be interstate. Could someone help me out... I had my tires rotated and balanced, and that wasn't the problem... It still does it. Would this be alignment issues? or what?