I am looking for a rear differential to replace my 8.8 differential and I know I need a 9.75 my question is what is the difference between one with a tag number S918D and S919D, S941A, and S942A

 

I honestly don't know, but the 9.75 is a twelve bolt differential cover axle. it is considerably larger by comparison to the 8.8. worst comes to worst, pull off the cover to identify the ratio by the ring.

 

thats the thing some of the differentials that i am looking at have the same gear ratio and same size and they will both be disc but the only difference I can see from the wording is that tag number and I am trying to find out what they mean

 

usually, the tag will read something like this, at least in my experience, 3L55 975.