All Black Everything!
Ok so I have a lifted 2007 NNBS which I swapped out the gears to 4.88s. Did the break in for 2 weeks was just driving normal with the speedometer off by like 15-20mph, topping out at around 70-75ish. So I just went to San Antonio driving almost hitting top speed on the speedo but really going slower, I went to get a Blackbear tune, all went well the speedo was fixed and everything but once we were done and on my way back to Houston I notice that once I hit 70mph my truck starts vibrating really bad, i give it a little gas and it gets even worse so i had to drive back under 70mph which rode normal as long as stayed at 65mph, anyone know what might be the problem??