For a '94-'99 GS-R you will need to have the Type-R B-pipe extended by 4.5". Here is a picture of my lengthened Type-R B-pipe.



Larger image (cut and paste link): http://www.imagestation.com/picture/...8.jpg.orig.jpg

BTW, I had a 2.5" exhaust flange installed for a future JDM 4-1 header and a 2.5" hi-flow cat. So, my modified Type-R B-pipe will look a little bit different. If you just want to extend the B-pipe and use the stock flange, then you can just have the muffler shop cut the B-pipe about 4-5" back from the flange. Then a piece of 2.25" piping can be expanded on each end and inserted in between.

The Type-R muffler will bolt right on the GS-R B-pipe with no modifications.