I got a problem with my car, I think it just needs a rebuild but i'm not sure.

It sort of starts a year ago when i first got the car. Whenever I stopped the car would stumble and black smoke would come out the exhaust. Felt like the motion of stopping was causing it to flood out, so I replaced the float and the problem was fixed. Less than a year later it started doing the same thing again, but not quite as bad. Now its gotten to the point where it feels like its running on 6 of 7 cylinders at idle. A really bad stumble especially in gear. When I hit the gas it sort of hesitates for a split second then jumps forward as the car instantly starts running on all 8. At idle i can hear a popping noise coming from the exhaust, not sure if its just something hitting somewhere on the exhaust from the vibration, or if its a backfire through the exhaust. Its a constant ticktickticktick noise. As soon as I rev it up it sounds like its running fine, but I can smell strong exhaust fumes like unburnt fuel and if I run the car real hard and then stop i smell a rotten egg kind of smell. Brand new cats on it.

I'm leaning towards it needing a full carb rebuild cause it hasn't had one for about 4 years at least and I put 40,000 km on it in the last year. But maybe it just needs a new float and/or accelerator pump?

Doesn't seem to be any vaccuum leaks. Car doesn't idle high and theres no whistling noises or anything. Starts up instantly every time as well, hot or cold.

btw this is a non cc carb on an 87 LG4. All stock except I just put 2.25 true duals on it. Just wanting to check with you guys before I go and spend a few hundred bucks on a carb rebuild. Thanks