On Saturday I went to the muffler shop with a new hi-flow cat I bought from Lordco. For kicks we took off the cat and replaced from the flange off the y-pipe to the muffler with a 3" straight piece of pipe. I drove around the remainder of the day with this setup, and I must say it made a GREAT improvement over the stock piece with the cat. Revved quicker and produced more hp and torque everywhere, quite a bit more resonsive throttle, but was considerably louder with torquing it at low rpm's.
We stuffed in the hi-flow at the end of the day and that pretty much took away all the gain that removing the cat gave the truck, pretty close to anyway. I do belive the hi-flow gives a weeeee bit more jam overall.
This Saturday, custom Y-pipe to replace the sick, choked-off "T-pipe" I have now. Hopefully it will be comparable as running with no cat at all!
Will post results tomorrow night, fingers crossed!