I presently have the Gibson sweptside cat back. It is not what I am looking for. Here is what I am thinking of doing for a dual exhaust.
Install X pipe to DI/DO Magnaflow cat to Flowmaster 40 DI/DO and run 2 3.5"x12" Stailpipes out the stock location. I'd like to keep the piping down to either 2" or 2.25 all the way down to keep low end.
I would like feedback and suggestions on how to improve this idea as well as how to make it work. My goal is to produce a great V8 tone, gain power, and not lose low end. Maybe it's impossible. The only way to know is try it. I just want to make sure the idea will produce a gain and not a loss. Also, I'd like to keep everything stainless steel. So if someone knows a muffler available in SS that is the same sound as a FM 40 or better, please let me know.
And for those of you that don't know, the Superduty exhaust is very different than the F150 to start with. It has a y pipe after the manifolds that dumps into a single cat and then to a muffler and tailpipe. There are only 2 o2 sensors before the y pipe so I don't have to worry about messing with those.
I've decided not to go with headers. It's just not something I want to get into at this time. I want to optimize the exhaust as much as possible from the manifolds back. I've read that the stock cat is already high flow enough. This may be true, but it is still a major restrictor of sound. I've heard it first hand. And since it illegal to add another cat, I have to stay with one. Oh, and that's that other thing. It's for a work truck so everything has to look legal.
Any help or suggestions is greatly appreciated.