Anyone have any upgrades to a Vortec 350 Chevy that do anything? Doug Thorley headers only claim like 8ft-lbs of torque and like 5HP increase. Hardly seems worth the time or expense. As I look around the only things I can see worth doing to it are, cam, blower, or head port work(the least worthwhile unless one of the other two is done). Anyone have experience with something actually improving power? I have the restrictor plate thing removed from my throttle blade, that and removing the silencer box is all thats done to the rig right now.