MSDS uses the stock "tuned" 180 degree bend & has a 2.5" outlet.
It dumps to the front on the stock cat or custom catback.
SHOShop is a direct downpipe to either a 2 in 1 cat or straight spacer pipe and a 2.25" outlet (IIRC it's 2.25")
It dumps to the stock cat-back location.
The MSDS Y-pipe is only available when buying the matched header set.
