Ray,
Run the grey gears. The white gears were the first batch of replacements and a prone to breaking. Probably would never break either gear in stock or 19 turn but at least you'll have peace of mind. Btw guys... Buy the chassis from Ray! You won't find a better milling job for the money. I got one earlier this year and love it. Balances the car and makes it feel more planted to the track.