[dsraven]

you can use a piece of threaded rod between the lower control arm and the upper hat to fine tune the lower control arm "level" angle and also to keep it there when done the fine tuning.
it's really important to have the rake angle figured out and have the frame sitting at that angle when you mock up the cross member and ifs. I noticed the rear wheels have an air gap above them and the front wheels are a little bit tucked in with no air gap above them. not sure if the front end is where you want it and the tire sizes are the same front to rear but just wanted to mention that. if thats the look you like then all good, otherwise you may want to adjust the rake angle before finishing the mock up and welding in the cross member in place.the wrong mock up rake angle affects the wheel alignment for the rest of the truck's life.