[dsraven]

when it is all said and done your lower control arms should be level, from inboard to the outboard (the threaded rod adjustment. thats where the steering is engineered to be when driving around) and front to rear (the angle of the subframe). that would set them correct for when you are at ride height. if you do that and then install a wheel and center the wheel how you like it in the wheel opening, for front to rear and for the look you like at ride height, then that is where the frames will need to be when it comes time to tack them together. make sure the truck frame is sitting at the rake angle you have chosen as well. a lot of guys use 2 deg down in the front but it is a personal preference thing. you can also use a plumb bob to make a mark on the fllor to check if the axle centerline is parallel to the frame. that is an important step.
good luck and keep posting pics if the progress.