the hard hot starts are probably being caused by the carbs slightly flooding over. A cold engine will not be too bothered by the excess fuel leaking through the carbs but when hot it will flood out.
I would first check fuel pressure to make sure its not too high. If that's OK then take a look at the needle and seats. If they aren't closing properly that could cause fuel to over fill the bowls and drip out of the boosters. If they are ok then I might take a look at the main bodies. I've done 2 sets of 2x4 Ford Holley carbs lately and they all needed the main bodies machined flat. Over the years of countless rebuilds and heavy handed wrenchers they tend to distort and need to be machined flat again.