2006 screw 4x4 just put a 2 1/2 inch level on it and now on the first test drive there is a loud squealing at about 40 mph under accell. Anybody have any idea what this could be. Nothing is hitting or rubbing

 

Make sure you didn't accidentally bend your backing plate during your install, causing it to be pushed against the rotor. I know that wouldn't be affected by speed or acceleration but it's the only thing I can come up with.