While I have no skin in this game, these are an excellent candidate for anyone who is seeking to delete their secondary catalytic converters (for non-highway use).
Simply Dremel off the end of the cat, remove the element, and then reweld. Thus 100% eliminating any fitment issues as a result of using some of that non-OEM aftermarket pipework, and while saving your original pipes / cats for potential future use.
Very stealth!
DM