Quiet muffler choices

I called Walker's technical service line this morning and asked about the flow numbers for the Quiet flow 3 mufflers. He told me that they don't have those numbers listed with the spec's for that line of mufflers. But, that they typically flow 290-320 SCFM. After talking to him more about my concern regarding a restrictive muffler and sound he suggested using their Bullet muffler 24215 as a resonator upstream of a Super Turbo muffler. The Bullet is short glass pack, removes the drone associated to the Turbos. Once I get the tail pipes I can see exactly what size and offset mufflers will fit and go that route.

The link above Auto Exhaust Science, discusses the formula of HP X 2.2 = flow. If my motor makes 350hp it needs 770SCFM of flow. So it will need more flow than what the Quiet Flow 3's will give.