I would watch out if you're going to run aftermarket headers (true duals) on a close to, or otherwise stock motor. I had a set on my 95" HQ build and they were great except I felt they were too loud.
A friend of mine tried them on an '08 SG (96") with 211 cams, SERT, and Bassani Powercurve headpipes. Could not be tuned, period. Bad stumble off idle.
They went over to a friend with another '08 SG (103") with 255 cams, SERT, and Samson TDs. Just fine.
I've seen them on stock bikes, and heavily modded bikes, but the key seems to be staying with stock headers on anything less than a strong build.
Nothing out there sounds like a set of CFRs. They were just too loud for where I reside. I have gone to a set of SE stock muffs with a 2" Fullsac recore. No apparent loss of power where it counts and a full 7 db less at idle than the CFRs.
Z