2. The Magnums can be ordered in different ratios, but we chose the version with a 2.66 first gear and 0.63 sixth gear. If you want to run really low gears, like 4.10s, or maximized mileage on the highway, they do offer one with a 0.50 sixth gear. Either way, all Magnums share a 26-spline input and stout 31-spline output shaft. On the rear of the transmission, just below the shifter, is the reverse lockout solenoid, and just below that is the port to run a mechanical speedometer, should you choose to do so.