3inch suspension lift swb GQ still got the shakes

[GQSWB]

ok ive looked up what needs to be done to eliminate driveshaft vibration, its a swb with 3inch susp lift n 33s, so far its got 10mm gearbox spacer, 3deg castor correction for radius arms and f n r driveshafts have been flipped.
its still got bad vibration, just so i dont over spend, what should i try next or in what order, should i drop the gear box another 5mm, ext control arms (upper or lower?), panhard rod, drive shaft spacers???

[GQSWB]

if i drop the gearbox more can i just add another spacer to the 10mm one thats there or do i have to replace itwith a new one at 15mm thick

[GQSWB]

im just guessing at 15mm itll prob need more

[threedogs]

Ring Micheal at Superior Engineering.