Plugs are still good, but clean them because the carbon can cause them to loose spark (shorts thru carbon). I applaud you for installing a wideband O2 sensor. With A/F in the 10's, you probably have black smoke from the exhaust. You verified that the choke plate is full open when it runs rich. The main other thing to cause "too rich" is if the fuel bowl level is too high, or overflowing into the throat. That is commonly caused by debris in the needle seat, which is easy to remove and check in most carburetors. The float can also sink, but your carb is fairly new. One other thought is if you have the "heated air inlet" as in ~1973+ cars, if the diverter door in the air cleaner sticks in the "hot air" position, it can run rich. That happened to one friend in a Ford Escort soon after those things came out. On a long trip, they started getting 10 mpg and found a stuck door was the problem.
Ill give the plugs a clean, and I am sure I did have some smoke coming out, it was running like crap! The choke was good and the carb looked nice and clean inside. And I have an aftermarket air cleaner so its just the filter element sitting on top. The fuel was the culprit though!