I'm not sure if they made a noticeable difference when I used them...also not sure about the reverence paid to Doctor Diff but he is well respected so you think he would offer them if it was a viable option as implied; me thinks he does not as he buys them already assembled. Usually depending on the condition, one of the first things I do when buying an old Mopar is put on front disc brakes and rebuild the front end using reasonably price kits found on Ebay...with free shipping. I thought about getting new uppers with the ball joints and bushings installed but it is pretty easy to change them out...especially if you have the right socket for the ball joints. For the upper and lower bushings I usually use a combination of pipe nipples,nuts, bolts and washers to remove and install them. By the time you buy all the parts and pieces to do the job yourself your probably saving about $30/40 bucks sourcing Moog parts from Rock Auto over buying the the control arms already done....and still having the offset bushings.