Actually.. I bought the DJM Uppers as a ' template '. Their unused and ' in the box '.
Theres 2 ways to properly lower an ' Edge ' and 1 just isn't really ' happening '.
A set of arms, or spindles.
The problem with spindles.. You will need HUGE wheels ( over 20 inches ) to clear the lower control arm if the spindles main shaft is mover upwards ( which will make the vehical sit lower in front ). In doing spindles, you also have to account for the brake calipers and wheel berrings.. Theres a LOT of design work in the parts that have motion.. Fatigue of the parts also has to be looked at as well as heat transfer on the spindle itself as the caliper brackets can act as a heat sink and pull braking heat onto it.
The second option.. control arms.
Re-engeneering the control arms is a LOT easier. The only motion of parts that needs to be worried about.. upwards and downwards travel. The balljoints are used for steering and radius movement.
The ' Upper arms ' just need a plate and a pair of tubes to connect the plate with the balljoint to the frame. Essentially, it just keeps the location of the top part of the spindle stable. The lowers need a type of ' z ' to them to move the lower balljoint upwards and for frame clearence reasons. The lowers also need a ' socket ' for the torsion bars to enter into and keep stable.
One could ( I would purchase a junkyars set to do it ) take a pair of lowers, cut them, use a plate standing vertical to essentially move the lower arm up ( HINT! ). Keeping it in proportion to the angle created by teh upper.. No more balljoint worries as everything will be correct in angle and the joints will sit in a vertical fashon.
Its a simple ' trig ' equasion thats easily solvable once you figure how much of a drop you want, how much suspension travel you will need, and how much your willing to fork over to pay to have it done ( or for parts if your machining it all yourself ).
You CAN use keys. Its YOUR truck. I would suggest getting a new set of upper balljointns ( whole arms ) with a ' lifetime warrenty ' before hand as you will ' bottom ' them out on occasion and they do not like such. Its good to have the option of beinng able to replace them and not have to keep ' buying them '. The sad part of such is you will probably need an alignment everytime you change that upper arm as it bolts right to the frame and usually has a camber/caster adjuster on it that you need to remove to change the arm itself.
An XLT setup is the best way to go BUT, you will have to change/weld a bunch of items. The lower control arms of an XLT are roughly 1.5 inches shorter in width then an ' edge ' and the difference is split between both the lower mounting points, Thus you will have to grind off the current lower arm mounting points and re-fab ( attach ) the proper positioned XLT setup.