"H-pipe," X-pipe," or no pipe?

I have an x-pipe system from DR GAS (with 30" boomtubes..similar to NASCAR). I am REALLY happy with this Exhaust system. They have dyno tested their systems and it quiets your system down 12-15 decibles with zero HP loss when compared to open headers. It cost me about $900 for the parts, and $250 in labor to pay someone to weld it and install it. It sounds SICK! Check out these pictures and videos. Send me a private message if you want to talk off line about it. You can hear my car with open headers and after the exhaust has been installed (skip to the middle of the video) at [ame="https://www.youtube.com/watch?v=cDkwrmhScIk"]1965 Plymouth Barracuda tribute car: Pat Clark - YouTube[/ame] and here is similar system on a 65 chevelle at [ame="https://www.youtube.com/watch?v=pYRzU6OLefs"]Dr. Gas Boom Tube Muffler Exhaust Build for 65 Chevelle - YouTube[/ame]

here is their website http://www.drgas.com/xpipes & http://www.drgas.com/Boom-Tube-Muffler_p_32.html (I went to their factory in Salt Lake, met with the owner, saw them being built). What quiets the sound down are the half circles welded into the chambers...very cool). You will have to paint them and cut them to whatever angle you want if coming out the sides, or leave them alone if going straight out the back).