What are the differences between the various years of KA24DE

[internetautomart]

I currently have 4 KA24DE vehicles in my possession.
1 runs and drives but has the normal KA motor noise (timing chain slap) (91 S13)
1 has had the motor removed for use in another body (93 altima wrecked)
2 have bad motors (97 and 99 altimas)
I want to know what, if anything, prevents me from dropping the 93 motor into the 97 or 99.
From my research, the 97 motor has different lower intake and exhaust manifold than the 93 motor. 99 I haven't researched much yet other than that 98 is a direct swap (97 is by itself)
In our preliminary look my buddy saw some extra sensors on the 99 motor that he didn't recall being on the 97 or 93 motors.
I also noted the obviously different distributors between 93 and 97 (99 appears similar)

[angrypenguin182]

there are differences, most of them are found right here on the forums, search a little more it's all there