Revo gearing question

Ok, so this is my first brushless car and really my first time back into this whole rc hobby. I got my revo used and have been driving it around for awhile now trying to keep it going. I have put a fet upgrades on it but nothing like other have in this forum. I have broken a lot of things a arm rear diff slipper clutch 3 sets of axles and a few other things. I think the axles went because i didnt have an idea how to set the slipper but that my problem. So because my slipper went out i got a new one a robinson racing gen 3 clutch. It only came with two gear options 60 and 65 on the spur not knowing anything I got the 60. After taking my car around I noticed it was running a 68 and a 14. I am not sure if this is a good gear ratio to run and really have no clue where to start. So, here I am asking the people that know. What should I run with a 60t spur? I do a little bashing and a little racing all of it on dirt i try to keep my car off the road as much as I can. Any help would be great thanks.

[Overdriven]

A little more info like what motor and voltage youre running would be helpful. Also how fast do you want to go? Going from 68t to 60t is a pretty big change though. To do your own gearing calculations check out BrianG's calculator here: http://scriptasylum.com/rc_speed/_top_speed.html

Sorry about not giving you enough info. I go from 4s to 6s my 4s is running at 5200mah and my 6s is running 5000mah. Its on the brushless revo with the castle motor with the mmm esc.