Changing out my speedo gears from my M21. I know they are not stock as I changed them out when I changed to a 4:10 rear gear many, many years ago. They are currently an 8 tooth "green" drive gear and a 25 tooth "orange" driven gear. Does anybody know what the stock gears were for a 3:73? I seem to remember the drive gear was steel? I also have a purple 10 tooth drive gear and a 22 tooth green driven gear. I also have the Stewart Warner external gear reducer box that has a 0.8241 internal ratio. I know the tire diameter makes a difference, but I will be going back to the stock tires eventually so whatever the stock gearing was is where I want to go. Thanks in advance.