4 door dart dual exhaust

I would go down to your local exhaust shop and have them quote you a number for a 2 1/4 dual system all the way out the back. As for mufflers, flowmasters sound good, but will create loud echoing in the car at certin rpms, and turbo style mufflers will give you a more mellow tone. There is not a difference between the undercarage of a 4 door and 2 door dart btw.