Thats just a bit of burnt oil and condensation.Under that valve cover looks nasty, I have never saw anything that bad other than bent push rods and a blown apart lifter.
General light caking due to neglect.
I will wipe everything down, install new pushrods, bolts, rockers, and after the 3rd oil change it will be nice and clean.
A tbi 2.5 is a $300 air cleaner to oil pan engine to replace. That and they take a ton of abuse. They dont make enough power and have enough slop to run in some very abusive situations.
I have a 86 2.5 in the barn that I could run if I need to. I wont have to much of a issue finding another 91 longblock. They were put in several s10's and many of those aluminum bodied mail "trucks".
I had a 78 6.6 pontiac where the valve covers were packed with cake. The oil pan weighed around 10lbs when it came off. I never rebuilt that engine or pulled the heads. I just cleaned up the heads and oil pan. There was alot of gasoline involved to loosen and dissolve the oil. Once everything was good enough I filled it with fresh oil and fired the engine.
I brought it up to 180F and let it sit for 10 minutes while watching the oil pressure sit at a solid 30 psi. Then changed the oil and ran it for a week putting around 200 miles on it.
Changed the oil again then changed it every 3000 from there.
Thing never burned any oil or leaked.
I have saved several engines in the same manner. Do a general cleaning/gaskets then a short oil change before doing oil changes every 3000 from then on.
The valve covers are often clean within a year of driving.
Some oils advertise 10,12,or 15k oil changes. I often buy those full synthic or mixed synthetic for 5 quarts from $15-$20. The main reason I change the oil at 3k is not the oil it is because thats when the filter starts to get blocked.
A 2.5 is easy to work on. $25 and 10 minutes I can have the oil changed with 1 to 1.5 quarts left over.
This engine will be clean inside soon enough.