Whomever is telling you that the "H" pipe gives you more torque is either pulling your chain or selling "H" pipes. I'm making greater than 300 ft-lbs from 2800 rpm (could be a tad lower) on up to the redline with the "X" pipe. Sound is a personal preference. If you really want more torque, stop fooling with half measures and do the whole exhaust. While you're at it, cams.
300A
born 08-27-02
Adjusted air in and air out.
400+ timeslips.
When in doubt, GAS IT! This will either fix the problem, or end the suspense.