Its not that hard, and I think all cars were carbed back in the early to middle parts of last century. A carbed car can be made to run just as reliably as anything, but it takes tuning and effort.
I have 2 carbed 5.0 Foxes, and one efi 2.3. Had the 79 Capri since 81. Was originally a Motorcraft 2150 2 barrel.
I put a 4 barrel on my 79 Capri in 86 or so. With Holley 8005 carb, that had vacuum secondaries, 2 stage powervalve, electric choke, and a solenoid kicker for the ac. Had provisions for pcv and the fuel bowl vent to the canister, and enough vacuum taps for all the vacuum emission stuff, and worked with egr. Connected to the original c4 kickdown rod with a lever extension. Worked with the oem cruise control. With 622 pri main jets it would get 21 mpg highway at 70 mph, avereaged about 15 overall. Ran low 15's. It was setup to be a daily driver and was my prime family vehicle from 1981 until 1993. I put a Holley 80457 on it a while back, perked it up some, but went down to 13 mpg.
One thing carbs will have, is less tolerance for conditions they are not set up for. If you have a worked engine, and set the carb up for top end performance, it will not be able to lug around and idle forever at lights with the ac on as well as efi.
You will have to focus the carb on one aspect and compromise on the rest. My 79 was always oriented toward street daily driving, and the ets always suffered because of it.
All that said, if I had efi, I would keep it. It's more reliable, more efficient, and takes power adders more easily. I drive my efi 2.3 more now than the 5.0's on a daily basis because it's less hassle. No cold start warmup, always idles, ac does not drag it down, and its quieter. And gets 25 mpg. Only when you get to 3-400 hp or more, in a drag race or similar performace setup will you see much advantage to carbing, and that setup will take as much tuning as efi. And it will not be very street friendly.
