[Green Machine]

If you don't have posi, it will be hard to get both wheels to turn together, likely the other side will turn backwards when you side is turned forward. Just leave one tire on the ground and turn the free wheel 2 times and count the drive shaft. If you want to get real precise, turn the wheel 20 times, if the driveshaft turns 41 times even you have a 4.10, 45 1/2 turns would be 4.56 etc. Actually this would be a good time to pull the rear cover and put in new lube, then you can find the tooth count stamped on the ring gear, should see something like 10 41 which would be a 4.10 rear.