ive got a 94 fleetwood with a 5.7L. i want to put an exausht on it, i got dual flowmaster on my 89 fleetwood but its FWD so they said i would have to have a box then it would run two pipes out of the box. It sounds good but i want it this time to be really loud and throaty sounding. I want people to hear me way down the street. If i run true dual flowmasterall the way to the manifolds will it make it sound the best? and what are catbacks? I heard one time that they reduce your power but sound better?