Well I read through all of this thread, as I have strange brakes front and rear. Below I copied and pasted a post I made some time ago in my Kama Kaase thread with regards to the weight difference between the 9 inch and 8.8. You may be surprised:
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Guess what I got today?
A BBA 9+ rearend from Currie! 35 spline axles and a 35 spline spool. I measured everything before taking it out of the box and it looks to be exactly correct. Won't know for sure though until this weekend when I put it in.
Something very interesting and surprising! I weighed the 8.8 rearend as I am shipping that off to Zman, so I needed to know the weight. With a detroit locker, moser axles, the thicker aluminum cover, 3 inch studs, with fluid, it came to 190lbs.
Now, I weighed the 9+ Currie. Granted it has a spool, which is lighter, and it had no fluid, but this thing does have 35 spline axles where the 8.8 has 31. It weighed 185lbs. Checked it twice. Who knew?
Zmans rearend: