Not sure I'm understanding how you plan to use the dynomax muffler? Are you talking about using one in where the muffler sits in front of the tank, like the pypes SGF70?
The dynomax 17553 is meant to be used like an X-pipe. That means both inlets on same side of the muffler. I'm not sure it's going to work if you tried to use it in a cross-flow. If the inlets were on opposite sides of the muffler, part of the exhaust pulse would try to go back upstream on the opposite bank.
Pypes Crossflow has both pipes going through same muffler body, but they do not directly intermix:
