i have a 9-turn double motor in my B4, i know it probably sounds like over kill, cause the regular is like a 12 turn right? but what kinda gearing should i put in it? i have the stock spur tanks in advance

BAR 26

this may help
http://www.teamassociated.com/racerhub/other/gearing.htm

b3-b4 have the same tranny,, don't they?

No the b4 tranny is based of the gt. It has a gear ratio of 2.60:1

So aproximatley what gears should i run?

I generally start 7 teeth over the amount of turns. Then tune from there. I would use a 16 tooth to start. Hope that helps.

thank you thats exactly what i was looking for!!