8. Our ’49 CJ-3A has run 5.38 ring-and-pinions since leaving the Willys factory all those years ago. To match this ratio, we ordered up a rear 5.38 JK ring-and-pinion from G2 Axle & Gear along with a full install kit. Dynatrac recommended a 35-spline ARB Air Locker to provide that extra traction that our Flattie needs. Luckily for us, our ’49 already has an ARB Air Locker up front to match.