I don't really feel it's necessary these days with all the muffler options and crossover pipes. An X-pipe and good set of mufflers can be pretty quiet, especially if it has tailpipes.
My 9 second DartSport had 3.5"pipes, X-pipe, Magnaflow stainless race mufflers and the pipes exited on the side right in front of the rear tires.
People would tell me they thought I coasted into the staging lanes because they couldn't hear it.
My current mid 10 sec street car has 3" pipes, H-pipe, Jones stainless straight-through mufflers, and 2.5" tailpipes.
It is very quiet and I love the sound. But I do have electric cutouts for fun and track time. I haven't made a pass yet with the cutouts closed.  I was shocked at how quiet my car was when I first put on the 4" Hooker Max Flow mufflers. They are straight through, like a Dynomax Ultraflow, but are real quiet at idle and part throttle. I have an H pipe and dumps at the axle. Have not done a back to back test yet, but it's run real close to what it has w/ just a pair of 4" race bullets on the collectors. 
CHIP
'70 hemicuda, 575" Hemi, 727, Dana 60
'69 road runner, 440-6, 18 spline 4 speed, Dana 60
'71 Demon, 340, low gear 904, 8.75
'73 Chrysler New Yorker, 440, 727, 8.75
'90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt
'06 GMC 2500HD LBZ Duramax
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