Outer Limits 4x4 Board

I have recently fitted some 75 series front leaf springs into my GQ leafy. they give close to 4 inch of lift over standard and are 2 40mm longer than the standard which is good with extended shackles because it allows them to work properly. i got four 3 degree castor wedges as a start, 2 for the front to help correct the castor and 2 for the rear to try fix pinion angle on the tail shaft as the uni near the box is doing all the work! i have fitted the wedges to the rear and made the vibrations worse! yet to fit the front! 35's fit no dramas now without body lift or guard cutting which is what i wanted to achieve!

any suggestions on the castor ?

is there a way to know exactly how much it is out?