Originally Posted by Scotty85
Having drag raced Mopars for years, I can assure you that you can definitely have too much exhaust. It doesn't surprise me that you lost low-end power when going to a larger, more free-flowing exhaust. You will almost always lose bottom-end torque. Engines do require some back-pressure based on the rest of the combo in order to have enough scavenging for proper combustion. The only way around that is if you have the heads/intake/cam to make up for it. You could always add a higher-stall TC to try and make up for the loss in the bottom-end. The higher stall would get you up in RPMs past where you're losing the torque.
Throw a set of 3" true-duals from the heads back and remove the cats, regardless of which muffler. See how much bottom-end you have then. It'd just lay over and wanna die.
I've always been told/educated in your second sentence as being spot on.
However, your last paragraph, while you nailed it in theory, is NOT an astute move to undertake. Removal of catalytic convertors is a serious Federal and emissions violation that's just not worth the benefits in lure of the consequences should you be pinned.