318 4 bbl and intake upgrade

Let me make myself more clear on this, if you convert to a 4 barrel carburetor and just bolt it on then it's at least a 15 horsepower gain, if you properly tuned it, it's good for a 25 horsepower gain. Either way, the modifications that I mentioned will make more than the 17 horsepower that you mentioned. Tuning is where it's at
Your numbers are totally Arbitrary and dependent on engine size, condition and tuners ability. IMO, you lack experience.