500hp 408 with Hi-Po 340 Manifolds?

This is what headers are all about. Air in, air out. I run a 408 with eddy heads, rpm air gap, etc.. and it originally dyno'd at 498 hp and 528 ft/lb torque. It's a little more now, but if I took the TTi's off and ran straight manifolds I hate to think what would happen. It would choke off a ton of horsepower. If you already have the TTi's, why are you considering anything else? I love my headers. Two years now and clean as a whistle. Good sound, good power.