Not sure of this is right place for this, please move if necessary.

I just acquired a complete engine harness for the Eclipse. Im curious if the "gunk" that's on the plugs is normal and there for a reason. Maybe keep connectors from corroding? Better connection for the plugs? Or is it some type of mold, residue build up? Curious if I should clean up before install or its there for a good reason and let it be. Thanks.

That looks like old dielectric grease or possibly lithium. Dielectric is used to prevent corrosion and promote conductivity.
Not to worry. Just give a blast w/brake parts cleaner and remember to use fresh dielectric grease when you hook up the harness.