Coolant leak above starter... below exhast manifold??

[1-ton]

I had one SBC that had a leak at the rear of the intake manifold gasket..

A couple of years ago when I installed my new crate engine the engine developed a leak that was dripping right at the starter, and it turned out to be the thermostat housing. Since engines are designed to lean back a little on their engine mounts, the coolant was running towards the back of the engine along the right side of the intake manifold, and under the wire loom that runs along the right side of the intake manifold, which caused it to be hard to see.

 

[imiceman44]

I'll bet it's a freeze plug. I had one corrode thru on my 64 C10 in high school. It would have been 28 years old at the time. An 87 motor is older than that now so it's not improbable.

There is a freeze plug right behind/above the starter.

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Same happened to me.
I just poured some block seal and drove it for 5 years until I sold it.

 

[Wes Harden]

Pull the #8 spark plugs and check for steam clean. Look at the back of the intake on that side. Coolant can leak out back and run down block at head seam drip, by starter.
You have aluminum intake and it blocks the head coolant passage, alot of electrolysis happens here.