Thunder manufacturing also makes 2-1 pipes for the mean streak. I talked to them and they mentioned that it will increase performance. Here is theie web site.
http://www.thundermfg.com/Pages/streak_fi.htm
Scroll down and click on the picture of the orange mean streak with their pipes. That's them.
This looks like a very good pipe. If it does offer the performance of the Muzzy pipe, then it makes it even better, and with Thunder manufacturing, you could buy the 2-1 pipe, the Tornado air intake and the powercomando all together from one place. They even pre map your powercomander, with their dyno tested map, for the best performance with this combination. I guess you can't beat that. However, personally, I did like the look of the Hard Krome Xccelerator II pipes better.
Kind of interesting side note here... When I talked to the Muzzy guys, I mentioned that Thunder MFG also makes a 2-1 pipe. Then their mood changed and they quickly said, "those guys copied our design." I then changed the topic, did not want to make them angry with me.
There are other posts here of guys that have added aftermarket 1-1 pipes to their mean streaks. You just have to search for them. They usually include very detailed information about their power gains and personal comments. I found them to be very helpful.