I have changed so many king pin springs for death wobble . most were old as hell and sagged out .
but yes I have done some with the crane eliminator kit . truck had 10+ year old swamper tsl on it 44" size and you could do 60mph on highway just fine . also did the bronze bushing upgrade on it .
the kit was installed in a fresh remaned king pin kit done 60 and I figured 1 shim per side . got it together and greased and couldn't even turn the knuckle . pulled shim out and just crane eliminator and she was good and had maybe hair more drag over stock spec when turning the knuckle.