Carburetor size Question

There is nothing wrong with a 224/110 cam; I got 32 mpgs with one; cruising with gears the equivalent of 65=1600; but it took a boatload of ignition timing, that you cannot get out of the distributor by itself.
Oh and my 68 Barracuda slices thru the air pretty easily compared to say, a 76 D100, lol.
So I know that cam has the potential to make great fuel economy. The only problem with it is ; mine had 53* of overlap, so it really wanted to be up at 2000/2200............. which I obliged by traveling at up to 85=2100 keeping up with traffic.
I remember how my Uncles used to brag at Family Gatherings in the early 60s, that their old Buicks and Oldsmobiles used less gas at 85mph than at 65. Now I sorta know why.

The model that I outlined, was for; power with economy and a killer first gear. It's just a model, based on my life experiences. It was precipitated by your saying that you already have an adjustable valve gear (which doesn't usually come cheap), and your close to sea-level elevation (which puts you a leg up in the pressure-making business, over most of us). Blessed with these, your 328 at 9.75Scr, will feel and be more powerful, than a similarly-cammed lo-compression 360, at 1000 ft, at least from idle to maybe 3600rpm. The 360, according to the Wallace, at 1000ft, would need an Scr of 9.3 to better your sealevel combo, below about that 3600rpm. But even thus matched, your 318 has the potential to get better fuel-economy.