For the tranny measure the diameter of the pressure plate...
The d-series has a diameter of ~212mm*
The b-series has a diameter of ~220mm*

* Pretty sure, but #'s are from my memory, can someone validate?
Yeah having it Ported and Polished will help to flow some more air...
Just look for a writeup on how to do LS/VTEC...
I need some more information to help u anymore...