I have a 8.8 rearend, confirmed at the dealer, and with the tag, plus 10 bolt pattern.

Just had to have the rear seals and bearings replaced, and they used the 9.75
Is this the norm here? This is for a 2004 F-150 Supercrew with a 4.6 I bought used with 65k on it, and as far as I know, all stock. I have read the post were as the 9.75 rearends used the smaller 8.8 bearings, but could find nothing in my searche's as far as my truck goes.

 

If you are talking about the axle bearing and seals, the 8.8 diff takes a 6408 bearing and a 8835S seal. The 9.75 diff takes a R1561TV bearing and a 100357 seal. That is 1 per side, so 2 total per diff.