Dude! Go with the whole system. All the way or nuttin'.
You'll end up doing it anyway.
You must re-jet if you re-pipe.
" For every action there is a ....reaction....... bla,bla,bla....
I guts a Graydon full, k&n, no airbox lid, and a 112 main replacing a 93.
Now i can give roost from my 250ex!