I want more Hp for my 318

67 318 is supposedly a little higher compression than the later years. Supposedly.

A cam would definitely help, but I'd keep it very much on the small side. Too much will kill it, and anything aftermarket will be a huge improvement over stock.

If you install a cam, then headers would be a good upgrade, though they are an MF-er to install.

The vacuum secondary carb is fine. I ran a 670 cfm street avenger on mine to good effect.

Gears are a definite must. Minimum 3.27, more if you can deal with the high RPMs.

Torque converter would probably be the best bang for the buck upgrade assuming your trans can hack it.

Good luck

Steve