'59 Ford Fairlane Custom 300 /ISO carburetor help
So I've got this beautiful '59 ford Custom 300. Love him to death. I was told everything in it was original when I bought it, shocker, its not. Now im having Carb problems.
The day we bought it we couldn't get it to idle. We adjusted some stuff and got it going but it was still idling suuuper high. for the first probably hour we drove it, it would get going and then maybe 5-10 minutes later you could feel something give out and it'd die while you were driving, we'd pull over and it would immediately start back up and go, but we noticed some sticking in the butterfly and general gross-ness, so my dad told me I'd have to rebuild it. It was a 7 hour drive back home, but we got it back with very little issue. There were several times after we got it home i tried to drive it out, and it would start mostly no issue, but it was still idling high and would still just kill itself every couple minutes. When it dies it smells like fresh gas and my exhaust is black plumes, so I assume my carburetor is way over-feeding fuel and flooding itself while running.
I went on a search for a kit, I got everything disassembled and cleaned and put back together and maybe loosely? tuned. While doing so, I noticed that the carburetor tag was not fitting with what should have been on the car if it was original. Its still an Autolite/Motorcraft 2100, but the tag reads to a 70s model ford instead of a '59. I didn't think this was going to be an issue until I realized the venturi sizing on the two carburetors seems pretty different. The original should've been 1.02" and the current is 1.23".
Im at the tuning stage. I have the manuals for a '59 and I'm trying to tune it the best I can but I can't get it to idle more than 5 seconds to adjust the idle screws, the carburetor just keeps flooding. I tried just screwing in the screws more but im horrified of accidentally messing them up I tried adjusting the choke plate open more, but theres literally no measurement for how "open" it should be in my manual. I just keep getting a whole bunch of conflicting information about what to do for the choke plate, (ive heard it should be completely open when warm and ive heard there should be a measurement which seems conflicting to me) and ive also heard that because the venturi size is different i should maybe put smaller jets on the engine because the air is moving slower so having the fuel move slower could help fix some of the flooding? Or that the venturi size difference could be messing up the vacuum? I dont know. This is my first endeavor into a classic car. I feel like im drowning in information and none of its helping. Im 20, my dad is 40, I think ive worked on more cars than he has but they've all been modern cars. im getting into auto service classes in the fall but I know its going to be more modern engines than anything like this and I really dont know where to go to ask these questions. I tried r/ carburetors but they were little to no help. Just told me there should be measurements and specs. To follow the '59 specs and "just tune it like any other carburetor, dont overthink it." Its all just kind of frustrating because i am a beginner and I feel really out of my league here, when I try to ask for help I'm not met with anything actually helpful. I know this isn't an advice subreddit, but if anyone can point me in the direction of others I can ask for help it would be wonderful. There's some car shows coming up soon in my area that I plan on going to and asking questions, they're just not for a few more weeks and I'd like to be able to get all of this pinpointed before my brain explodes.
If anyone needs like, literally any pictures of anything I can get it to you.
tldr: I'm new to old cars and cant figure out what's going on with my carburetor, no amount of research I've done has been helpful and neither was the other subreddit I tried. Id like help if possible or help finding someone who can help me.