A few things to consider as you plot your path.
Carburetors are increasingly expensive and difficult to repair. If you can find a rebuild kit cheap and the car is just an occasional driver, that might be the best path. My 1965 Newport came with a Bendix Stromberg WWC 2 bbl which gave 18 mpg on the highway (65 mph limits then). But, carbs are problematic and it stranded me a few times by idling rich (sooted the spark plugs = mis-fire). Other problems are fussing w/ chokes, leaks, even spilling fuel which can start a fire. For a regular driver, consider a throttle-body fuel injection. There are several now w/ integrated electronics that replace a 4 bbl carb and even look like a carb. No cutting wiring holes thru the firewall, self-tuning so little skill required, and some cost <$1000. You can save that much in fuel in a few years driving. Also, the engine can last longer since carbs running rich (esp. cold engine) wash oil off the cylinder walls to cause rapid wear. If you do go EFI, the main problem is delivering high-pressure fuel. There are under-hood systems now that leverage the existing tank and single fuel tubing, pricey but easier mod. They also require an O2 sensor in the exhaust, but I recommend that even for a carb and wideband O2 is cheap today. The days of removing spark plugs to judge color and decide "rich or lean" can be forgotten. BTW, if you need a new fuel tank, search here. The CR9 works (B-body ~1970 Roadrunner, ...) and is much cheaper than rare C-body ones.
My 1965 Newport is in-work. Around 1996, I installed an aluminum 4 bbl intake and a Holley 2D Pro-jection EFI and O2 feedback. That was always problematic, requiring constant tweaking of the control box knobs, and even exploded a muffler from a brief "fuel event". I will change to an Offy dual-port intake and Holley Commander 950. I do have Quadrajet and Thermoquad "spread-bore" carbs I might play with. Those were the apex of carb design before the 1980's electronic feedback types, and give the best combination of mileage and performance, but are increasingly hard to restore.
