i was also wondering if an exhaust made for an type-r (not type-r exhaust) would fit a 00 gsr. from what i've read it does but not too sure yet.

i want the full comptech exhaust setup but its not a constant flow of 2.25". the header is 2", hi-flo cat would be 2.25" and exhaust is 2.25"... but that's OD.
so in that case ID would be 1.8--->2.25--->2.20".