That will give you a 6.4 to 1 ratio. I don't run 16" rear tires, but I think you might be lugging it pretty good. I would think maybe somewhere around 7.5 or 8 to 1 would be a good starting point. I run 12" rear tires and run ratios from around 5.5 to 1 to 6.5 to 1, depending on the track.