If you must gut the pre-cats, just get them from Dallas Mustang or your local performance shop that deals with Mustangs. I paid about $70.00 for them and they have a male/female connection, which makes installation a snap

Recently I had to send them back because one was bad and I have a new pair on the way, great customer service! The guy sent me an email telling me to just be careful when installing them because you don't want to mess with the board thats between the male/female connections. All this being said though, its not worth gutting the pre-cats...IMO.