Pinion Snubber Question

walked out back to the bone yard, there sits the 7.25 diff from the 68 Barracuda, OE 225 Slant Six,, and the diff has a pinion snubber,,

so,, just asking here, what was Ma Mopar's plan with the pinion snubber?
1) why did my slant six, 904 tranny and 7.25 diff combo need one?
2) did the Commando, 383 Barracuda and the later 340 Dusters cars also get a snubber?
3) What about the other guys, back in the day, Cameros, Mustangs, AMC,, did they use pinion snubbers?
4) when was the Mopar pinio n snubber introduced and why?

thanks
Yes! I have been wondering about it too...

I bought one from a guy on here that was all nice n painted, but I am not quite sure why I need it... Although I have my suspicions why, as my set up is powerful and such...