I want more Hp for my 318

If you still have the stock cam in it you will need something bigger to make real use of the 4bbl carb. I am running the stock 340 cam in mine and it works well but like others have mentioned there are better more modern grinds. You are probably leaving over 50 HP behind with the small stock cam. I think your carb is just fine as long as it's not mechanical. The secondaries will only open as far as air flow demands anyway. I run a 600 holley on an old streetmaster intake on mine and power much better then stock and MPG actuall increased too. Most 318's will pick up around 100 HP over stock with cam change, 4bbl carb and good exhaust with headers even using the small port heads. Also be sure your getting full throttle at carb, if the intake and carb has been changed and the linkage not modded or changed you may not be getting WOT as the 4BBL stuff is different from the old 2BBL.