Read Dave Shannon's pages.

The job will be easier if:

You decide to do a throttle body cleaning with the TB off the car.

You decide to put in the 1988-type PCV system. Means new oil separator, new hoses and a re-located flame trap. Benefit is 15 second flame trap service.
(My 1986 has old type low-level flame trap, my 1988 has hi-level, dunno when they changed.)

You decide to replace the intake manifold gasket. Harness goes in simpler with the manifold away from the block.

You decide to replace heater hoses - easier with intake manifold moved.

Look over the job and the extent of the harness. Does it have the wires that go to the alternator? If yes, consider replacing the three accessory bushings on the alternator, you'll have to get in there anyway. Be ready to clean the grime and what-all off the bottom of the engine front.

Good Luck,

Bob

:>)