The F-111 Aardvark: How might it be different today?

F-111 could go faster than that. Some aircrafts max speed is limited by thrust and other planes, its an airframe or temperature limitiation.

F-111 could do Mach 2.8 even with the D model. I would not be surprised at all if the F model had the power to hit Mach 3, but who knows when structural failure of some kind would happen.