Still running rich
I had a 440 very similar to what you now have. I ran a 750cfm AED carb on it.
Drove it and bracket raced with it. some may say this setup would be lean. However, the car ran mid 7's in the eight mile at 3550 pounds, and the EGT readings were always around 1350 to 1370 degrees. It ran great on the engine set up as follows:
jet -- 78's front, 80's rear
Power valve front -- plugged
Power valve rear -- plugged
The float levels were set to be at or just above the half way point in the sight glass.
If your carb has plugs and no sight glass, set the float level with the engine running and the plugs out. raise the floats until fuel just BARELY starts to seep out.
Idle screw settings may vary, but if you have to turn them out over 1 turn, then something is wrong. remember that the further out the 4 corner idle screws are, the more fuel that is being pulled. Mine was perfect at about 3/4 of a turn out from seated.
Fuel pressure has been mentioned. around 7 to 7.5 lbs is about the limit in MOST applications. not saying a car won't run more, because I know some who run around 8 to 8.5. just saying you don't want 10 freaking pounds blowing past the needle and seat.
I would start by doing these adjustments one at a time, and sneaking up on the carb tune. Don't make to big of an adjustment at once.
After that, if you are still rich, I would then move on to the suggestions that everyone has given. Lot of smart guys here on the forum. My advice is to take one suggestion and try it before moving on to someone else's suggestion. that way you know what worked and what didn't without getting way out there with so many changes.
good luck.