Need some opinions on how to make more bottom end power in my 2500. Its the TBI 350 with 4l80E. When I jump on it with my new exhaust she makes a lot of noise but thats about that. Doesn't really pick up when it hits passing gear. Kind of sad when you consider I have 4.10 gears. I have a K&N FIPK2 and removed the cat and replaced with a Flowmaster 40. Plenty loud but not much in the go department. It did get a little quicker with the exhaust but not much. I ported out the throttle body for better flow but as far as I know the majority of the low buck mods for TBI motors make Higher RPM power. I am looking to produce more power lower in the Rs. Is my only option new heads and cam?