OK now you know what size U-joint is used on the rearend. A good rule is to use the same size U-joint on the transmission side. If you already have a yoke for the transmission that has a smaller U-joint than the rear pinion yoke then you could use an adapter U-joint like this one. The U-joint can be used for a transmission yoke that has a 1310 U-joint and a driveshaft that is 1350 or vice versa. For me, if money was tight I would match the rear U-joint (1350) to the driveshaft (1350) and replace the transmission slip yoke (1310) later down the road to the larger 1330 or 1350.