Dallas, I did some playing in the scryptasylum calculator assuming you are running on 3s with 77/24 gears and 4.2 inch tires. The calculator says 63 MPH.
I run 83/24 with 3.6 inch tires. With this gearing it calculates to about 50 MPH. With this gearing it runs at safe temperatures.
To calculate this to go to 63 MPH I would have to add six teeth to the pinion or increase the tire size to 4.2 inches and add two teeth to the pinion.
The calculated number is pretty meaningless at these speeds since you have drag and tire expansion as countering effects that complicate things but it gives you an idea of how differently we are geared.