Just to share the information... I decided to take the cats off of my Bassani x-pipe. Before and after runs on the dyno showed a loss of between 5 to 10 lbs of torque throughout the RPM range. The hp stayed about the same, a loss of maybe 1 or 2 hp here and there. I will be putting the cats back on this weekend to gain the power back.
With cats = hp 286, torque 310
Without cats = hp 284, torque 304
I just though you all would like to know.

Also on a side note, I installed 4.10 gears. They are great. It feels easier to get into the power band. I have a manual trans and it doesn't feel like I'm shifting constantly. They are Ford Racing gears and there is no whine. Great mod.