Jason,
Before you change out the headers, try flipping the motor mounts around, so that the tabs are at the bottom. There is a picture of the motor mounts for Ridetech Velocity Camaro on pt.com. Rumors had it that Dynatech used Velocity to develop the headers (post 57 in below link). I swapped my mounts around and gained roughly an inch.
http://www.pro-touring.com/threads/4...493#post372493
Just a thought, unless you absolutely want a new set of headers.
Tu