castor correction is just that, less kickback through the steering and not as much wandering over the road. at the moment your diff flange is running at an angle pointing upwards (with the lift kit)when the castor corrected arms are fitted the diff flange will come down towards the ground as per the standard angle, by doing this it will knock out uj's even quicker than what you are experiencing now. My advice is take the lift kit off and throw it on ebay