64 pitch is fine. much quieter anyway. more fine tuning with 64p. around a 3.7 to a 4.2. 88/47 is a good start. but get some smaller pinions also. say from 41 up to 47. then you can go from 4.29 down to 3.74. all depending on track size and temp. motor temps in the 130 to 160 range are perfect. any hotter and motors start to fade on power. i like to keep mine down to 130 ish.