4 link question??

[handy67]

so i got my lower control arms back on and truck is sitting much better now fully aired out. took the truck out for first drive this past sunday and ran good first time. after pulling it back in the garage adding some tranny fluid i attempted to go back out. when i went to pull out i gave her some gas and the rear rotated back and put the u joints in a bind. im thinking maybe my u-bolts on the rear arent fully tightened down? i have no idea and am learning as i go, this is my first bagged and 4 linked truck ive worked on. Any ideas or things i could check would be much appreciated. thanks all.