as stated many times before, keys are unnecessary... as far as a ball joint flip and a dif drop, I drove mine around for 2 weeks without, and after doing them, I would definitely say it is a must... if you are going to max your torsion bars, you will most likely bind the ball joint, hence the necessity for the bj flip... and unless you want to replace cv axles every couple of years, as simple of a task as it is to drop the dif, it would be senseless not to do it... a "kit" is going to run you about $300 with no ball joint spacer, and no dif spacers... pick up a set of 2-2.5" shackles off ebay (bent not welded) for about $60... call larry at suspension max and pick up 3/4 spacers for the dif, and 1/4 spacer for the ball joint... all together you are looking at $250 for a setup that will function and ride much nicer than the... "kit"