Pinion Snubber Question

I think the non-adjustable OEM ones were intended to keep the car from completely bottoming out, no way a factory /6 car has enough HP to use it in a performance manner. The adjustable snubbers are meant to control axle wind up as mentioned above. They also aid in weight transfer - (again, this is a racing application) - when you hammer the go pedal, the car squats rearward - if the snubber is in there correctly, the "floor" of the car lands on the snubber giving you more down force and supposedly better traction during launch.