318 Cam Maybe Not

The intake and carb upgrade will provide the greatest gains followed by the dual exhaust, cam and head upgrade. Upgrading the rear end (you’ve probably got 2.76 or 2.94 rear gears?) to 3.23 would be your next biggest improvement after the carb/intake upgrade. As others have said, the cam upgrade would help but given the other work required when replacing a cam, it wouldn’t be as noticeable compared to the simpler carb/intake, exhaust and rear gear upgrade. Depending on what year 318 you have, you might not have much in the way of emissions meaning your distributor curve won’t need to be tweaked as much. Mine is a ‘75 so to maximize the gains of fewer emissions (ie: EGR) I upgraded the distributor as well.

I started out with the same base 318 setup as you and did the LD4B/1406 upgrade, later 340 exhaust manifolds, 2.5” dual exhaust, replaced the 7 1/4 2.76 with a 8 1/4 3.23 end and also upgraded the distributor curve. I’m really pleased with how the upgrades have woken up the 318 (well 323 since it’s 30 over).