There is no such thing as a self locking nut.
Its a nut and a bolt, stop trying to reinvent the wheel here..
"btw", if you rather jack the car up higher then you need to, then keep the wheels on. Im sure there are steps that can be done faster/different, then my How_To post stated.. it was ment to be a very straight foward, info packed post to follow, even for the weekend shade tree machinic.
My How_To was to help guys that had no clue going in to this install, feel confident that they could do it with a little time and the correct tools. Its nice not having to pay people for things you can learn to do yourself.