I had dw when I installed my rc 4" lift. I searched and did all the basic checks: tires balanced, track bar, tie rod ends, ball joints, and had it aligened many times. I also had three different sets of wheels and tires through all of it. I thought maybe I had junk rims or bad tires. I finaly replaced my control arms with the adjustable version so they could adjust my caster. Death wobble is and has been gone ever since they were installed. I can hit bumps and drive at any speed without even a hint of dw or shimmy.
I'm not saying this will fix yours but adjustable arms are nice to have anyway unless your planning long arms in the near future. Good luck.