ALIGNMENT PROBLEM

[JRZ2500HD]

My brother just bought a used 03 1500 z71. The dealer did an alignment and put new tires on the front. He has 4000 miles and I noticed him coming down the road and the toe is way out. But when he backs up the toe goes the complete opposite. The top of the tire probably moves a good 3 to 4 inches. It basiclly looks like when you go forward the front of the truck raises then when you back up the front end squats. Thanks for anyone with any insight.