just call him. Matt will hook you up with thte right flange. who knows sometime you will get a better price if you call him.
send him email for his number on ebay.
but yes that should work for you. make sure you put lots of high temp rtv on it when you put it back together.
maybe replace the fmf with a different pipe...

j/k
I don't remember the FMF having the ability to seal with an o-ring flange.
Q pipes used aluminum, but I think current pipes use steel flanges.
The aluminum wasn't all that durable.
A new pipe is not in the budget right now.

I like my machines to look nice. But the looks of the exhaust flange doen't matter. I just want the leakiness gone. Next week I'm gonna get the pipe off and get the inlet and flange really clean, then glop it up with some ultra copper permtex and re-install, for now. But today, I gotta ride!
i thought they were called Trailer Queen's. lol
Oh, and here I was thinking they were called drag queens.
I would use ultra grey semi-rigid permatex instead of the copper. It will hold up better in your application. It is the only silicone I will use on a QR motor.
Thanks for the heads up on the Permtex ultra grey. I'll pick some up and give it a try. Gonna hold off buying the billet flange for now.
load it up let it sstart to set up then put together and just finger tight bolts, then a day later tighten up all the way.