corral.net has a speed calculator try it. but the last i read the higher the gear ratio the less top end but i could be wrong plus your RPM'S and MPH will be off thats why they made speed cals so youll know where your at exactly your speedometer may say it's doing 140 but youll maybe be only doing 120 115 peoples speedometer are usually of by like 10 to 25 mph off but like i sid i maybe wrong