I have no idea how to rebuild...especially the third member...I have an open chunk , 28 spline...and I have a limited slip unit to put in it...I know its not as simple as dropping it in...any info would be helpful...links maybe?
First of all, rebuilding a 9" is not really something you want to try on your own the first time. You will have to set up back lash and pinion depth. You will need a dial indicator, a stand for it, plus pinion shims. If it is done wrong, the gears will be noisy and will die prematurely. It is normally better to pass this on to someone who is experienced.
Now to answer your question--By far the best information I have found on rebuilding the 9" is in my 66' Mustang shop manual. It has numerous pages with pictures and diagrams. There are little blurbs here and there on the internet, but this book is by far the best. A must have.