Think you really need to open up the Idle Feed Restrictions on the Primary Metering Block. Stock 3310 Vacuum Secondary carb has pretty small ones. With any kind of a camshaft the engine needs more Idle Fuel/Transition fuel to not run really hot.
Here is a link to a picture showing the location of the Idle Feed Restrictions.
https://www.google.com/search?q=Holl...bs%3B600%3B399
The picture shows putting a wire in the restriction hole, we want to actually open up the hole size.
With a 455 engine, I would make those .038" in size vs the size that they are now.
They can easily be opened up with a "Pin Vice" and a .038" drill bit by hand. The brass restriction drills very easily.
If you can't do it yourself, PM me and we can work out me making the mod for you.
Tom Vaught