What are your opinions on Edelbrock SDT muflers vs flowmasters, and which way would give the best sound and performance? I've listend to the SDT muflers on youtube and they seem to have a nice rumble to them.

#1. Staying with a dual in/dual out mufler, keeping stock y and tailpipe.
#2. Same as #1 but adding dual tailpipes out the mufler.
#3. Adding two muflers routing it back into the factory Y-pipe after the mufler. or
#4. True duals all the way if theres room with the quadrasteer.