Headers or Cam?

Needing some advice from the experts out there. I've got my dual exhaust, e-fans, True-Flow Intake, and Nelson Tune. So obviously I need something else to do now...

So which give the most low to midrange - headers or a cam? Also, stupid question, but do headers bolt up to the stock exhaust? I assume there would be minor fab work to do, but nothing substantial, correct?

dunno about newer models, but im assuming the exhaust headers will bolt right in, although they may warp over time if they are poorly designed... also... the headers wont give you huge power gains that a cam will give. i dont know what kind of performance camshafts are available for newer engines, but it is not too hard to make an old-school 350 put out well over 400 horses at the crank and 430+ lb/ft of torque somewhere in the 3000's rpm range. the key to picking a cam is to choose for your usage... in a daily driver, dont put a huge cam in or else you will loose a lot of low end torque as a trade-off for high end power. for a truck, peak high rpm power is not very important given the fact that you need more low end torque to get that 5000+ pound hunk of steel moving.

so combine the right intake, cam, and exhaust headers, and you will make huge power levels, although i have no idea how to program a computer to know that the cam is bigger or something... also, i wouldnt worry about getting aftermarket cylinder heads to replace the vortec heads because those vortec heads are very good in the low and midrange and stand up to many aftermarket heads pretty well.