did the 87 nc23 and 88 nc23 share all the same engine parts? namely i'm asking about the clutch and crank. thanks.

I'm not 100% sure but don't think a great deal of engine internals swap between the 87 Aero snd 88 Tri Arm, unless I'm mistaken the Aero didn't have gear driven cams :)

I'm 99% sure the 86-87 Aero/Hurricane had gear driven cams. It even has "CAM GEAR TRAIN" written on the fairing.

The best way to find out on compatibility is to seach through the parts book. I think theres one in the docs library but if not try cmsnl.