Was that a hight flow cat you used?
Yup. It's the one which
Rodney Dickman sells. (go to the "Engine" tab of his page, and look for
Replacement Catalytic Converter.
Including shipping & whatnot it worked out to about the same price as a high-flow stainless steel cat from local sources, plus extension pipes, plus hassle. A 20 minute install with a saws-all or other handy cutting tool to remove the old cat.
The only thing I'm not entirely pleased with as far as Rodney's cat goes, is that the s/s clamps he includes. The extensions which mate up to the OEM exhaust are 2 1/8", but the clamps he sends are 2 1/4". Then again just try and find a 2 1/8" stainless steel muffler clamp.

I ended up spending another $4 at CTC for a pair of proper size mild steel clamps.