I have the same set-up, an LSD in a 73. Contrary to popular belief, you don't have to change the half-shafts. I don't know why that is the prevailing wisdom. You do need to pop the stub axles out of the diff and put in different ones. I used two from a '75 280z.
I forgot exactly how I solved the input yoke problem. I know the choices are to modify the drive shaft or to get a new input yoke for the diff. I had previously replaced u-joints and balanced my drive shaft so I opted to change out the input yoke. But I forget what year I had to find to make it work. You have to match the spline on the diff to the early drive shaft. PITA! In retrospect, probably the easiest thing to do would be to acquire a '87 drive shaft, take it to a shop and have them cut the end off, cut the end off your existing drive shaft and weld new onto old, grind, balance etc.
I forgot exactly how I solved the input yoke problem. I know the choices are to modify the drive shaft or to get a new input yoke for the diff. I had previously replaced u-joints and balanced my drive shaft so I opted to change out the input yoke. But I forget what year I had to find to make it work. You have to match the spline on the diff to the early drive shaft. PITA! In retrospect, probably the easiest thing to do would be to acquire a '87 drive shaft, take it to a shop and have them cut the end off, cut the end off your existing drive shaft and weld new onto old, grind, balance etc.
