If that's all you want, this is an easy question... Answer: 1:1. That's because in high gear, any non-overdrive trans has a 1:1 direct coupling. We'll ignore transmission or coverter slippage at this point.
To calculate theoretical top speed, you need to know tire diameter, gear ratio and engine rpm. You will have to pick a target rpm to figure things out. Let's say your engine has a theoretical redline (rpm limit) of 6000rpm. Lets say you have a 3.00:1 rear gear set. That means that the axles will be turning 2000rpm. With a tire diameter of 26", that means your tire circumference is 81.3". At 2000rpm, you'll cover 162600 inches in one minure. divide by 12 to get feet = 13550. divide by 5280 to get miles = 2.566 and multiply by 60 to get miles per hour = 154.
Now this is all theoretical. At speeds greater than 40mph, you have aerodynamic drag of the car body to deal with. Well, it is a factor below 40mph, but a small one. the faster you go, there is a marked increase in aerodynamic drag.
I have calculated several theoretical top end speeds with a rev limit of 6000rpm and a 26" tire diameter.
rear end ratio speed
Your rate of accelleration is all determined by horsepower and torque of the engine.