^^
What he said for sure.
Other things to check for:
*Hows you clutch? If it's worn replace or upgrade, whatever you want.
*If you wanna put in a lightened flywheel, now is a good time.
*I replaced my throw out bearing, even if it's still useable, just replace it, they're inexpensive and you'll be pissed if you have to drop the tranny again for that little thing.
*Check the gears,my revers was all grinded up
*I dont know about a rebuild kit but PG sells a kit with stronger gears. It comes with 1st, 2nd, (no 3rd), 4th, and 5th
*Check all you syncros. I went through all of them and a few were worn out.
*Oh and be carefull with the oil pick up, it made of plastic and breaks real easy.
I had to drop my tranny twice so my whole thing was "If its worn, I'll replace". This way you have a better chance of not having to drop you tranny again for a long time.
(It sucked my second time cuz i had class the next day so i pulled an all nighter just to be there. Of course, i stroll in a little late and my teacher lectures me about being punctual.)
EDIT: Missed the part about the clutch, sorry about that, and you probably already know this but get you get your lsd welded. Good luck!