I have a no crank condition with my 88 firebird, 350 swapped. I have power on the big wire (battery to starter). I have continuity between the purple wire that goes to the small terminal of the starter and the thick yellow wire on top of the steering column connector (which I understand is the start wire) This is with the key in the start position.

However, I have no voltage going to the purple wire on the starter when the key is in the start position.
Can anyone confirm from this info that it is a wiring vs starter issue?
​​​​​ thanks

 

Check your neutral safety switch, needs to be in park or neutral or the switch could be bad. Other than that you should see a red wire at the ignition switch, that should have 12v all the time. If not, you have a fusible link either blown or not connected correctly.