Mike you can tell what gears you have just by spinning the yoke and counting how many turns it takes to make the drums to make one complete revolution. In other words if you have to turn the yoke 3-1/2 times it's a 3.55 gear. 3-1/4 times would be a 3.23 gear. You can also tell if it's a sure-grip by having a buddy turn one drum and you try holding the other. If their locked together it's a sure-grip. If one turns one way from the other it's an open.
Check to see if it's an open or sure-grip before you do the gear count cause if it's an open rear you have to have 2 guys turn the drums exactly equally one turn and count the turns of the yoke to get the ratio. Kinda opposite of how you do it with a sure-grip.
BTW: if it is a sure-grip chances are real good it's the good Dana powerlock cause that's all that came in the 742 case. Hopefully nobody has changed it.
