AFAIK, 1984-up has the torx.Here's a question what year did they go to torx screws
Up through 1983, they had flat blade screw heads. Sometime in 1983 they may have swapped to the torx. But best as I can remember it was AROUND that time frame they did the change. It's possible some later 83 carbs had torx screws. But I'm not 100% sure on that.