Joe,
Unfortunately, the problem you're experiencing is the nature of the beast. The only known solution is to slow down in corners, and what fun is THAT?
I suggest you retire the original carb, or sell it to a concours guy, and invest in a decent Holley; make sure it is one of the models featuring center-pivot floats (i.e. not one of the cheaper "economy" replacement carbs) or you'll be right back where you started.
Depending on the extent of your motor modifications, a 600-700 cfm will probably be best.
Good luck!
Mike
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