Need Help

I have an 87 250x frame. I am putting a 93 300ex motor into the frame. I am lost for words when it comes to the wiring diagram in the book. Do I need to literally run every wire on this diagram for this thing to run or are there basic components that make this thing run. which components are the ones that i have to wire up and which ones are the not so important components.:icon_question:icon_question: