I agree w/ your thinking Larry. If you really want to do something, I've put a few ideas up before, but here are some random thoughts...
1) Hedman shorty headers, 2-1/2" Y-pipe into Flowmaster 2 into 1 Y-pipe connector. 3" high flow cat into 3" exhaust out the rear. A little illegal due to headers, but they really don't effect emissions.
2) Same system w/ cast iron RA III manifolds. Would easily pass for factory smog stuff.
3) Install a set of flanges on both sides of the cat. Install a "test" pipe for off road use only, of course
, Then you can reinstall the cat when it's testing time.
The 3" system w/ no cat will be rather rumbly. I've got a factory 2" pipe into a 3" cat w/ 3" 2 chamber flowmaster on a 76- very throaty even w/ the cat installed.
John