there are very few diff.s it will drop right in of course but you will have to use the obd-0 harness and keep your fuel injectors from the old motor and use you original dizzy.
there’s also a couple of sensors off the back that you’ll have to swap off your '90 motor onto the '92 motor, if you use the obd-0 harness. The holes are already there for them you just have to take the plugs out that are in them and put in the sensors.