Ben, to retrofit a can from one make to another, can be easy, or complicated. My mech once fit a Muzzy's mid pipe and can onto a Hindle header I had on a 90 1100. Required a little welding, but can be done.
Yeah the problem is when you start calling these people most of them don't stock the stuff and in the case of Yosh a lot of it is dicontinued. I think the only pipes Yosh makes for older GSXRs is the mild steel Zyclone. The Euro makers seem to be a lot better about making good stuff for older bikes, you could try ordering through a Euro source like M & P (www.mandp.com, though their paper catalog is a lot more complete) shipping would be steep but not too bad and you also wouldn't have to pay taxes. I think Remus makes a stainless system for those years too but there aren't too many places in the US that stock Remus stuff. I think Hindle is your best bet if you want a stainless pipe since they're pretty easy to get in the US. Star Cycle claims to have a lot of pipes but when you actually call them it's the same story, not in stock or discontinued.
I am wondering if anyone has (had) a mild steel Zyclone system instaled on thier bike. Currently I have a Vance&Hines supersport system on mine, but would like to replace it. Kinda curious if anyone could tell me if the yoshi is a tad quiter than the V&H with the quitech 1 baffle (which ever is the louder of the two)
Tnx in advance
If anyone is interested in the yosh zyclone at MAW for 345.95 (mild steel, stainless can)
They now only have two left. They also said it was all they had left period that would fit the 88-89 750. There were 3, but one is now mine.