Do these require two sets of gaskets? I would imagine you'd need a gasket on both sides of these flanges. Also who makes them, and can you possibly provide a part number? In the meantime... I'm gonna head over to Summit to start poking around. Thanks for the input.
I did find them made by Patriot. Both Summit and Amazon are out of stock. I ordered a set of Remflex gaskets. I think they are 1/8" thick. Hopefully that is enough. I really don't want to be grinding again.... ugh.