I have a 1989 D100; RWD with open differential. I am trying to upgrade to a limited slip. The anti-lock brake system is deleted. In speaking to my local junkyard, he said he had one but application is from 1973 -1988. It is a 10 bolt cover, "C" clip axle, drum brake setup. any help in figuring out, exactly what I need will be much appreciated. If it is easy, I would also like to switch to rear disc brake too.