Update! All done.
We put the new Dynatech cat on yesterday. First I took measurements, then I took off the test pipe supplied with my Hooker cat back system. I took this test pipe and the new convertor to a shop that stocked 3" pipe. I had them cut the flange off the test pipe, and weld it to an appropriate length piece of pipe. The other end of the pipe was then welded into the new convertor. Prest-o-change-o, a new direct fit extremely high flow cat.
It sounds, almost identical to the test pipe. It seems to be the same tone and number of decibels exactly. The only change is the drone (which was minimal already) is now even less.
I obviuosly haven't been to the track yet, but it feels just as strong on the street as before the change.
Lastly, I drove directly to the yearly dyno emissions test. The results were as follows:
CO % x liters
Limit - 1.10
Result - 0.11 - Pass
HC ppm x liters
Limit - 275
Result - 64 - Pass
NO ppm x liters
Limit - 3600
Result - 239 - Pass
RPM - 2051
Dilution - 15.2%
So...I'm pleased with my choice so far.