Source for a new catalytic converter?

[chris.miller at infofoundry.com (Miller, Chris)]

What's the cheapest source for a catalytic converter for an '81?  I've got the TTuning downpipe and 2" cat-back exhaust.  Current cat broke off the rear flange, and it doesn't look like it's worth trying to weld it up.

So, I've got the 3 bolt flange off the downpipe, then an exhaust starting with a 2" flared pipe... need a cat with a flange on only one end.  Suggestions?  

--- 
Chris Miller
mailto:chris.miller@infofoundry.com