Bucho,

Not sure if you ever got an answer but I have the Saito 170R3 also, it is in my Super Stearman. I just bought the 200R3 for the GP WACO. The 200R3 has long flexable exausts like the 100 Twin. I measure about 11-1/2 inches. They enterchange with the 170R3 and might work for what you want.

I going with a custom exhaust and will post it after it is done. I want the exhaust to exit at 9 o'clock like one of the YMF's I found to scale after.

Hope that helps,

jimm