[Formulajones]

The one issue with the sgf70 is pyoes cross flow muffler design doesn't follow the traditional cross flow design of the in and out configuration.
So that means the intermediate pipes and the tailpipes are all bent specifically to fit their muffler in and out configuration.

All other transverse mufflers have your more common configuration. Both inlets usually in The bottom and both outlets in the top.

With that said I'd suggest what jlmounce mentioned, adding a pair of resonators, and/or possibly using the factory hanger setup if you haven't already as some of the generic aftermarket exhaust hangers do tend to transmit more noise.