Used to be any kingfish over 25 pounds was a smoker, and you could feasibly catch one like that, seasonally, off any port in Florida. However, nowadays fewer and fewer of those big ones are heading to the smokehouse, due to state mercury advisories for kingfish over 39 inches.
But if you just want a big, fast saltwater fish to “smoke” your reel drag and give you a story to tell, check out Key West in winter and early spring, or the central and southern Atlantic coasts in early summer; these are places where kings occasionally top 60 pounds. Gulf Coast fish (with the exception of colossal kings on distant oil platforms) seem to run a little smaller on the top end, seldom larger than 40 pounds.