My speedo isn't accurate, as I have not changed it's gear since going from 2.73s to 3.73s, so I can only make a rough guess.
I backed off at about 120 mph at Pocono Raceway. My speedo needle was buried past 140, it looked impressive!!
The car was still pulling pretty hard, and the engine was turning around 3600 rpm, maybe a little more (too busy looking ahead at the upcoming turn). I have a 351W with T5 trans and 17" wheels.
Steve