Thanks for your response! I'll double check when I'm home later but I'm 99% sure I've got the stock 19f 55r. I'm thinking of trying 47 rear. I'm looking for better top speed - which doesn't mean I'm looking to go 90, I just want the RPMs to be lower at top speed. Also, I don't want to have to shift so rapidly. I don't need to be popping wheelies every time I take off on a hill. I totally bucked off the bike my first week. Embarrassing.
4 years later... I'm wondering if you ever tried the 45 tooth? I got a 1987 xt350 over the summer. It's my first bike. I'm using it mostly to commute on secondary highways and maybe 15% trails. I find the stock gearing frustrating for street use. When I first started riding I was unintentionally popping wheelies at red lights. I have to change to 3rd gear before I'm through the intersection. Then 6th gear seems useless. I'd like it to be less powerful in the lower gears and increase top speed and lower rpm on the highway. I don't need a torque monster. I need I commuter that can keep up with traffic and maybe hit the dirt roads now and then.