I have a 1995 K2500 with a 7.4 Liter 454. The truck has a heavy duty emmisions catalitic converter which sits behind the muffler. I have been looking for an exhaust for this truck for the past month with no luck. I want to cut the muffler out and just have the cat and straight pipe it from there back, the problem is that all the shops that I have been to told me that doing this will not change the sound of the truck at all since I have a heavy duty emmisions cat. Is this true? If so, how can I make the truck louder? The louder the better, any suggestions?

 

Instead of the stock 2.5 inch pipes, put in a 3-3.5" pipe, that should definitely increase the volume.
Also (not sure about other states) California does not require smog checks for diesel vehicles.
You could take the cat out and put a flowmaster in there. However if your state does require emissions testing
For diesels, or if they change their law in the future to require smog checks, you will fail without that CAT in
There and will have to buy a whole new converter for the truck to get it smogged.

 

I live in Virginia and I dont need to pass emmission but I do need the cat for inspections. My truck already has a 3" pipe and I just put a 4 1/2 " resonator tip on it. I was thinking about taking my muffler out and hollowing out the cat, the only problem with that is that it will rub back pressure and drop my horse power some. I was told by the Chevrolet dealership that they only ever produced 2,000 trucks like mine and with my luck I had to buy one that turned out to be a pain in the ***.