I recently installed a Mac two into to one muffler system on my Yamaha 920.I still have the factory exhaust system.  It's a very good shape and complete.  The only thing you need, are a few new gaskets.  I am asking $300.  Oh, I live in Campbell River British Columbia, Canada.

Do you like the Mac pipe?  I might be interested in your other set but I couldn't do $300.  If you want to get rid of them let me know.
Kevin Buck