When aquiring the 1.71 final drive ratio. Beside the 36 tooth diff gear you will need to use a shorter rear belt and different diff holders. I am not sure of the part numbers but hopefully someone on here will know them. I will check in a day or so to get the part numbers.
This car with the drive ratio is great. I also must say it is the first sedan car that I have used a smaller spur gear on than a 1/12th scale car. Note, I did run stock at Mikes Hobby Shop in Texas and Stock racing is so much faster with brushless than it use to be five years ago.