what needs to be switched

[sparepartracer]

I'm helping a friend switch a 90 4 cylinder hatchback to a 88 motor and ecm.What needs to be moved around to accomplish this.Do the pins in the harness need to be moved to different locations.Basically the reverse of a mass air conversion.Please help any advise would be great!!!

 

[Mustang5L5]

If this is a 5.0 swap he needs the entire engine harness. I beleive he needs a 90-92 harness and will need to use a Mass Air computer