What sort of mechanical issues will pop up if one were to get an ECM + 350 TBI from a '91 Brougham into a late 80's Fleetwood ?

Sensors that absolutely have to be there ?

Anyone have a wiring diagram that would help here ?

What about mating the current 200R4 to the '91 ECM - will this even work ?

Am I better off using the trans on the '91 vehicle ?

Thanks in advance !