I would try simply replacing your stock iron intake with a holley street dominator or M1 and see what that does. Should get you to pull a bit harder on the top end. You don't want to spin too much faster than 6,000 rpm anyhow with stock oiling. You still have the small pick up tube or is it upgraded to the Hemi style?
. I have to kindly disagree. The performer rpm intake is best for mildly upgraded 440. Its outta breathe at 6000rpm. Eddy heads with 84cc chambers and that intake, with this cam OMP Cams Xtreme Energy Camshafts 23-232-4