The final drive ratio in your Mini is one of the more critical items to establish seat of the pants performance. With a low numerical ratio you will experience great acceration but have to suffer with high RPM and resulting poor engine life if you spend much time on the freeway at current typical speeds. The 10" wheeled Mini as found in the original Cooper "S" had a 3.44:1 ratio. This provided good acceration but highway speed were best keep at 65 or under! With the advent of high HP output 1380's the favorite is now the 3.1:1. 12" and 13" wheeled cars should have at least a 3.2:1 final ratio. This same 3.2 ratio is also an ideal consideration for the 10" wheeled car with some reasonable HP and/or the need to keep both acceration and highway performance. This is the crown wheel (ring gear) and the pinion is DAM2808.