I finally got my 3" exhaust flanges, but they don't match up with the bolt pattern of my catalytic converter, and there would be leaks on the 3 sides. The final piece of my custom exhaust puzzle is a blank flange that's the same size as a 3" 3 bolt flange around the outside. I'm going to cut off the OEM converter flange, then have a new one welded in its place with the center cut out to the same diameter as the cat. This is so I can swap the converter in and out for inspection. Any ideas where I can find this?