My 87 Cherokee. Head and pistons/block. Does anyone see any thing concerning? I did notice a few coolant passages were blocked! I have since cleaned all of that mess. 260,xxx miles

 

Not really what you asked but the distributor cap and plug wires look like they came off the Titanic.

 

I am going for that "vintage" look.

 

Nothing out of the ordinary for 250k plus miles..get a new cap / rotor and a set of 8.5 mm taylor wires from amazon...keep on trucking. 250k + is where i stroked all of my motors....just because

 

Those are not coolant passages. Those are drains for sand that are used during the casting process. Your coolant passages are fine.
The straight 6 uses the two rear coolant passages behind cylinder 6, one small passage per each combustion chamber, and one return passage front passenger of cylinder 1 for use when the thermostat is closed.

 

The dark spot between 3&4 makes me think it needs to be resurfaced