I recently replaced the ford 2100 2 barrel carb on my 292 in my 56 victoria with a holly 4 barrel . The ford tag on the Holly was DOPF 9510 V which was meant for a Ford service replacement on a 1970 289. I believe the CFM is 450. Choke is manual. I would think this size carb would be just about perfect on a stock 292 being that I want originality, smooth idle, and decent gas mileage. By the way I am running the 57 and later 4 barrel manifold and the 292 is a 1961 model with the small valve heads. After the swap, the difference in acceleration was obvious . The car has much more pep now. Problem is, I quickly get an accumulation of black soot on the inside of my chrome exhaust tips and can see traces of black smoke when I rev the engine. Car idles smooth before warm up in drive with foot on brake in traffic but has a bit of intermittent stumble when warmed up. The carb was given to me by my neighbor who was a parts manager at a Ford dealership back in the 60's and 70's. He saved a lot of stuff when they cleaned off the shelves ( That's what he told me) His garage was a treasure trove . Anyway, the carb looked nearly new but had sat in his garage for at least 30 years so I put a new rebuild kit in it. I noticed it had #55 on the jets. I also set the floats dry ( upside down and parallel) . I am hoping someone can advise me on how to eliminate the black smoke  and stumble at idle at at the warmed up operating temp. One old timer told me I'm expecting it to idle like an old flathead and am being too picky. .
George