https://honda-tech.com/zerothread?id=956072 was a very informative thread. I didn't want to thread jack so I figured I would make a new post and add some info.

I knew a while back when I built my hybrid that I would have to make a trip to the muffler shop to chop up/extend my piping... I recently put together another hatch and found out that:

(THIS ONLY APPLIES TO B-series MOTORS)

LS exhaust manifold + LS cat + LS B-pipe + EH si rear section = direct fit

GS-R exhaust manifold + GS-R cat + GS-R B-pipe + EH si rear section = direct fit

an even better set up is a

usdm ITR exhaust manifold + ITR cat + CTR B-pipe + CTR rear section = direct fit

Hope this saves some of you hybriders some time after getting your swap done.