getting the front to lay on 00 fullsize

okay here is my delema. im doing a bag install right now on my budsied 00 fullsize. this is the first of this body style that i have ever done. i installed the kp rear kit on the truck. and i got fbi cups for the front. but the truck isnt laying out. the bag is collapsed befor the wheels even come close to hitting the wheel wells. does the truck need spindles or control arms? and the truck is only going to lay out on a 255/35/20. any help would be great. thanks in advance!