Dual Exhaust System Recommendations ?

Crossovers make a difference,even on the street.Many years ago my brother had a monza spyder with a wheezy 305 and a four barrel,he had true dual exhaust put on with an h-pipe.When we picked up the car it sounded quiet and bassy and after a couple days he decided he didnt like it so he took it back and had them cut it out.He was really dissapointed he did,we both could feel a substantial difference in throttle response and low end torque and was just not as smooth a driver.I have experience with a few x and h pipes at the track since and my results back up the tests you will find around the various sites.The h gives a little more bass and low end where the x gives a bit more midrange/upstairs and sounds a bit mellower/raspy.