I think the stock on mine before I pulled the 86 motor out was 12/42 but I'm not 100% on that.
It was ok I guess, pretty hard to tell because the motor went out before I could get it running right.
What type of riding are you going to be doing? That should play a huge role in your gearing. On our ltz400 we just dropped the front by 1 tooth and it made a world of difference.