I'll be in CD'A on Friday if anyone needs to have theses:
https://spokane.craigslist.org/mpo/d/coeur-alene-vintage-yamaha-yl1-gyt-pipes/7355548197.html (https://spokane.craigslist.org/mpo/d/coeur-alene-vintage-yamaha-yl1-gyt-pipes/7355548197.html)
I found a photo of a YL1 with these pipes fitted.
Mad machine.
IR8D8R
Even the headers are fat.