The GT does sound OK.....well maybe just a little too quiet.
I had planned to drill the muffler internal baffles until I looked at them closely. There is no baffle to drill. The muffler is just 2 parallel perferated pipes....1 inlet and 1 outlet.
My next idea idea is to drill a 1 inch hole from the exhaust tip end through the forward muffler end plate. Then cut in a 90 degree 1.5 inch pipe from the muffler inlet pipe to the hole in the end plate. That will create a straight path through the muffler. I'll try 1 muffler first to see how it sounds. If it is still too quiet, I'll do the other side. If the sound is not good, Magnaflows!