I edited this post from what I originally posted after doing a lot of research. My Jeep is a 1967 CJ-5 made by Kaiser with the 225 V6 engine. here is what I now believe is correct, much of this based on what people here have posted: Front driveshaft uses two Spicer 5-248X ujoints. Moog Precision 361 can be used in place of those as can the Crown J8126610. One pair of opposing bearing caps contains grooves that have c-rings snapped into them and these are the bearing caps that attach to the driveshaft. Those c-rings go on the inside of the driveshaft. This set of bearing caps also has a different diameter than the other set of opposing bearing caps. Rear driveshaft uses two Spicer 5-153X ujoints. None of the 4 bearing caps have any grooves in them because none use c-clips that go inside the driveshaft. The ujoint on the Quadratec website described as "Dana Spicer 1310" is the Spicer 5-153X because elsewhere on that webpage the part is shown as being the Spicer 5-153X. The description "Spicer 1310" had previously misled me to think this was a different part than the Spicer 5-153X. The ujoints used on the front driveshaft can't be used on the rear driveshaft and vice-versa. Feel free to jump right in if you think any of this is wrong.