I searched high and low for a replacement catalytic converter for my 2004 SVT ZX5. The SVT has a VIN engine number of 5; the converters for VIN engine number of 3 won't fit.
The least expensive one I found is:
RockAuto.com has it for $195.99 .
I found the same one on eBay for around $287.
CFM has a nice one for over $500. Dominant Engineering has one for $350, but they didn't respond to my emails.
The Davico cat has the pre-catalytic O2 sensor bung in the stock position: at the top. This is a Ford design fault that results in the O2 sensor being broken off often - I mean like two or three times a year.
CFM and Dominant moved that bung to the driver's right side of the converter (or the left side of the converter if you're standing in front of the car and looking into the engine compartment).
I'll have a new bung welded into the new Davico converter and the old one sealed.