X pipe vs H pipe

[ame="http://www.youtube.com/watch?v=FFqp7CIoR4g&list=FLBoJOlFj9k-6MoBfxKdf1Ng&index=27&feature=plpp_video"]71 Duster with Dynomax - YouTube[/ame]

X-pipe

Noticable performance improvement over standard duals