The ratio he is telling you won't work the same on your car b/c your dif gear ratio is different. I suggest an 18 / 58 combo you need to get the spur gear for a team assosiated Nitro DS. I've used every combo from 15/66 to 24/54 and the 18/58 with an .18 engine is a very quick combo. I can't remember off hand but im pretty sure i used a 17/60 combo to hit 54 mph and it had crazy take off.. The 24/54 combo was very slow off the line but at half speed the tires turned into pizza cutters and had a tendency to go on two wheels sideways. With the 17/64 it couldn't stop wheelieing coming out of corners and i lost a race b/c of it to another rc10gt but we both beat the jato 3.3 and so I changed to the 18/58. If your using an OS .18 cv-r you should be able to stay with a jato 3.3 on a 100meter oval.
I hope this helps.

O.K.