There are several reasons not to remove your cats. First, in my opinion, the performance loss involved in running cats is very minimal compared to the issues you will create by removing them.
Second. 1996 ahnd newer trucks have OBDII emissions which means there is a O2 sensor behind the cat that alerts the computer when the oxygen reading is out of parameters. Removing the cats will cause such a condition and set a code with the lovely check engine light. Now some will argue that there are O2 simulators out there for this problem but it has been my experience that they do not work on Chevrolet Trucks.
Lastly, removal may be very costly when you decide to trade or sell the truck. Most dealers will not take vehicles with altered emissions anymore and I have personally been involved with local government requiring an individual to take a vehicle back from the buyer after it was found to have missing cats!