That dual inlet outlet muffler should work for a balance tube if it is designed right. It could be two separate mufflers in one case. I think the two into one with one tailpipe one would be the best set up. The dual tailpipes might not have enough heat to keep them dry. Could be prone to rust out. The exhaust gas is already cooled by the time it hits the muffler so one 2" or 2 1/4" tailpipe would be plenty. You could always add a 4" fart can like all the imports are running
.
