I pretty sure Track Mode shift points were programed specifically for the quarter mile. They're not dummies.
Seriously doubt a human can do better.
I seriously doubt that you have gone higher than 6th, if that.
Believe me....that 6.4L in Track Mode is moving rapidly through the 1/4 mile. I haven't even given a thought about what gear it was in at the end of the 1/4 mile. I do agree that no way it would be in 8th gear. I don't even think it made it to 6th gear. Based on number of shifts I know it made it to 4th and I think maybe 5th gear. I do know that even getting near the traps and maybe getting a little out of the groove and the Scat Pack was getting a little squirrely as I was blasting through the traps.