From what you have stated above and the type of driving you do I will agree.
Yes you will get better performance with a larger carb at high rpm full throttle.
Also if any work is done to the 318 if you are looking at performance.
A stock 318 2bbl is maybe 350 cfm .
Now this is just me. Not wanting to start a fight. My favorite carb is the Edelbrock 500 cfm.
The carb for general use. I used a 500 on engines as large as a 451 stroker. Street driven.
