yes, i was wondering if the Lethal X will line up properly with the PHRP H pipe.I assume you mean the Offroad X and cutting it out and installing the H. You will love the sound from a off road H...
I would say it would work. they are all designed off the factory placement of the pipes so stuff lines up but depending on the size of the X it may have a issue.
That would be a good idea since Lethal's has been "In the work's" since September.
http://www.svtperformance.com/forums/shelby-gt500-150/711515-petition-o-r-h-pipe.html
We've had an H pipe for your 2011 available for sometime now, still working on the 07-2010.
I even bought and returned your X pipe because I just couldn't live and be happy with the X when it came from the factory with a sweet sounding H.