you need another mid pipe. If you really want loud go with an o/r pipe without any cats. I have a bbko/r x with 40 series deltas...loud as hell. Im sure I will get flack for this because you either love or hate the x pipe. Most people tend to like the prochamber or h pipe from what I hear on this site. I love my bbk, it has a real nascar sound to it. I know others on hear that like it as well. Go to mustangexhaust. com for clips.
I have magnaflow catted X with 40 series delta flows and it's the perfect volume. Since ur in cali like me, you could use the more reliable cats that come on magnaflow's pipe. its a smooth sounding combo, NO rasp, and still sounds throaty. I have a sound clip and a video i can share with you.
From what I have heard the h pipe has more of a deep bass sound to it, kinda like a old school stang with flows or any other muscle car without cats. It is more of a street car sound. But the x pipe is a whole other ball-game. It realy does sound like a nascar or something crazy. I will admit I love it, but it is so loud and obnoxious that im constantly looking for cops. It has a gurgle, hollow, im gonna kick yo a$$ sound to it. It won't sound like your adverage stang.
All I can say is that I have 40 series deltas witch are supposed to be quiter than the regular 2 chamber 40's. Mine is loud as hell, I can't imagine 1 chambers.