Outer Limits 4x4 Board

Im runnin RUF with some small missing links (60mm eye to eye) and 1" ext shackles. My steering feels quite "hard" even at speed, almost feels like understeer. Never lifted a leaf-sprung car before, but I get the feeling its got too much negative castor, which is the opposite to what I thought it would get when lifting it and extending shackles (positive castor) which would give the symptoms of touchy steering, with the wheels trying to "dig" when turning.

I've driven my mates sierra, running normal 2" ome fronts & ext shackles & even with big offset flipped rims on 31's it steers beautifully compared to mine.

Could the added bush/joint in the missing links (upper shackles) be causing "flexing" and making my steering funny? Is negative castor a common trait when doing a ruf?
Is there a simple diy way to measure my castor or do i need to go to a shop..?

Easiest way would be to get a wheel alignment done on it, shouldnt cost much and will tell you if anything is a miss in the alignment. Get the print out of hte specs and compare them.

Layto....