Physically it should. Yes, 73-76 discs were all large bolt pattern, 5x4.5. If you swap the k, I recommend swapping the entire thing including the steering linkage, much is the same as the 68, but there are a couple pieces that aren't and will be required to use the 73. Like the idler arm. Just easier to grab the whole thing. You'll also want the upper control arms off the donor as well as the spindles. If that 73 has a sway bar, get it and the lower control arms as well as all hardware.
