All Minis before 1973 used either yoke or flange couplings in the drive (half) shafts. U-bolts identify the yoke type and the flange type has a flange to mate to the corresponding flange on the diff output shaft, and uses a convention metal u-joint inside the coupling. If you are adding a LSD or flange output gearbox to a car not already equipped, then you need to buy outright as complete assemblies. Two required. Reproduction part, recommended for road-use only.
For race use, we recommend either 27H7880-USED, which are used original Rover couplings, or heavy-duty 27H7880SW Swiftune-developed units. The used units should be rebuilt before installation with GUJ0101HS genuine Spicer universal joints for best reliability.