XRAY - Model racing cars

New to racing and bought a Xray T2 006 from a friend. My club runs rubber tires on a small to medium size carpet track. I have a speed passion esc, lrp vector x12 17.5 motor and a xp ds 1313 servo. The question that I have is about gearing and I could use some set-up help. The guys at my track seem to prefer 64 pitch gearing, but I see that a lot of the team drivers use 48 pitch on the set-up sheets. Just wondering what is the difference between the two. Also will be running Jaco Blues tires if that means anything, but I am open to tire suggestions. Thanks for any help.