I know what answer he was looking for :)
Really what kind of real world torque gains are we talking here ? No matter what type of header, especially in the idle-3000 rpm where we spend very little time at full throttle and torque at these rpm only translates to 12-59% hp per lbs-ft of torque.
If the OP don't care about dollar value and wants to do it as an experiment with very little real world gains that kool. It just seems like there's an assumption there's a lot to be gained, just trying to put expectations in perspective.
