Matjow: Remember what I told you about your exhaust system? Also, note that Magnacharger only voids the supercharger powertrain warranty when EXHAUST changes are made. That should tell you something about where THEY think the biggest airflow gain opportunities are. This is why I am being so careful with my own supercharger install, keeping the shift rpm low for now, until I can get a good look at blackbox logged data.
On the other hand, maybe keeping that extended Magnacharger warranty intact is WHY you want to stay with that conservative exhaust you have? If so, I can't argue with it.
Matt - The AFR heads flow better out of the box then a set of fully ported 243 casting LS6/2 heads do. You would be better to get the AFR, you can get them just about anywhere, then sell your stock heads for between $500-$800 on e-bay or to a shop that needs cores to build for customers.