The hemi gains top performance at 5300 and carried it to 5600. The hemi totally drops off the charts at 5800rpms. Running past 5800 will gain absolutely nothing. Maybe trouble, but that's it. Seat of the pants perfoemance CANNOT be used as a tool. I have my Rev limitor set at 6k and max shift I have set is 5800.

The reason you may feel that it gets more performance by running higher is because when it hits the next gear you feel the kick a little more because you haven't had extra power past 5800 and the fact you catch the next gear in a higher rpms. i would call that a need to change trans internal gears or change actual differential gears so you get to that rpm faster and it hits harder.

 

I agree going by seat of the pants is not the way to do it. That is why I always do timed runs to see what effect the changes I make have. Without data to back it up you can never accurately gauge what effect a change has.