I don't know about the 318, but a cam kicked my hemi in the ass. But with efi I had to get (hemifever) to tune it. Free up the exhaust, free up the intake, could help a bit. Perhaps there are better heads that you can bolt on?
Inertia Spartan + cam, Circle D 3,000 stall ,Sonnax line pressure booster, MagHytec 68RE pan,and differential cover, Vararam, JBA's with cut outs, Rancho 9000's, Helwig rear sway bar,3:92's, extra rear leaf,Line-X Bedliner,GY Armortracs, 245,000 miles To Hell and back. 14.2/96 mph NEDW