the mondo muffler is made by bugpack...its a generic muffler brand. the dynomax will probably flow better on a high horsepower application. the sounds I'm guessing would be a bit different too because of different mufflers. also, the dynomax sits further in and the mondo sticks out a litte to let people know you mean business
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Those are some of the obvious differences, but you never know till you try them!
Stephan