I did the BBK headers with pypes x pipe with cat delete, sct tuner, and K&N intake. I was concerned with the volume so I kept the stock mufflers. I have a GT premium convertible. It sounds great at low end and idle, has a nice classic rumble to it. At cruising altitude with the top down I can still hear the radio fine and carry a conversation. It sounds great with extra pep.
force 2 system
Installed on a 2010 4.0L mustang. Pipes just make it but with some help I got it together. Sound is awesome no drone just loud enough. The hangers that come with system aren't painted. I would recommend painting then to prevent rust. I had previously installed a cold air intake system which makes the exhaust sound much nicer.