Yes they outflow until like stated up top until around that 550hp mark, so that being said once again unless you are putting out that kind of juice save you money. Unless you are going for looks under the hood it heeds no benefit from upgrading. You will get a little louder intake sound out of an aftermarket one. If you want though I would go AFE over banks any day. You won't see any improvement in mileage or operating temps until you are reaching those higher HP numbers.
2006 PSD CC FX4 Sport SRW S/B
SCT with custom tunes by Quick tricks, Grand Rock turbo back dual 6" Miter cut stacks,
Xenon Fender flares,Tinted factory tails, Recon white lightning L.E.D. light bar, Glasstite topper