So I just went to put my 3.54 diff in my 1031 casing and it appears my 1031 is so early the 3.54 will not fit.
If you have a 1986+ rear axle casing designed for a diff with a tone ring please let me know. I will need a picture of the inside to check it has the correct clearances.
If you look at this picture I need the one on the left....
i probably don't need anything except the casing but will take a whole axle if I have to and the price is right.
Cheers.