Anyone who says the 40 yard drill is a good thing for a tackle is absolutely wrong. For a guard who has to pull I'd say its far more important. As a tackle you arent running anywhere 95% of the time, it's your base and footwork that matter.
Tell that to the tackles which JT so often blows right by because they're too slow to keep up with his fast movement coming from the outside.
Uhhh that has nothing to do with 40 yard dash speed. Thats footwork like I mentioned. (And lateral movement)
How fast a lineman can run 40 yards has little to no effect on a game.