318 4 bbl and intake upgrade

If 17 horsepower is all that you can get from doing those 3 things, then you are doing something wrong. A 4 barrel swap alone is worth around 15 horsepower. Read on how the guys that run totally stock engines and see what kind of power they gain, it's more than 17 for sure.
You said before that a 4 barrel is worth 25. Now which is it? I'm out of here!