Nikkostars

First question, does the manual trans from the BL5(4th gen, NA, EJ204) match with the BE5(3rd gen, TT, EJ206)? Second question, what’s the best intake/exhaust setup? I’ve heard from a couple friends that messing too much with these(ie cold air intake/straight pipe) can actually hinder performance. Just want some more opinions on this from actual legacy owners.