actually, it does belong here because the questions are more geared towards basic datsun L6 knowledge. I will try my best to answer your questions.
The L6, in all the years it was made, L28, L26, L24, all have parts interchangability. So if something does not fit, there are some problems My girlfriend has a 77, i dont recall seeing any differences in where the turbo engine would effect clearance in any other way than the donor car it came from. The turbo will not hit the steering shaft, or at least what i see it wont.