Idle drop by 500 rpm?

You will have to fight with that one on your own.

I personally use the Edelbrock carbs because they are very simple to work on and adjust. Easy to get things to run right, and electric choke besides.

Plenty of other things to work on with these cars, I like not having carburation being one of the problems to have to work through.

Now if you are a racer, then that is a whole other can of worms.