I needed to swap out the collector on my 97 bird (dont ask why...) so I purchased a nice used one off of eBay. It said it was for a 97, but upon inspection it was slightly different that my original one. The right two and left two pipes on my original were joined together in pairs before the pairs came together, and on this new header the outsides and the insides are paired. By virtue of this design the scavanging should be, and obviously is different. My bike sounds different now. It's got a deeper note, the throttle seems "crisper", it seems to have lost some if it's raspyness at WOT, and I'd swear it was overall quieter.
My guess is the collector I got was off of a Fuel Injected bike, but it bolted right on and sealed up with no problems.
Has anyone here tried different stock collectors? Results?