After pulling the intake/exhaust manifold from the engine I spent some time cleaning the engine block on that newly accessible side.
It was definitely pretty cruddy with 50+ years of engine and road grime.
I used some Simple Green, which I’ve always found to be a very effective de-greaser, to loosen up the grime.
I used a heavy-duty scrub brush. The original color of the engine block started to come through.
I also used a rough Brillo-style nylon scrubber, working it in around the shift linkage and steering column, and even around the engine mounts.
I even cleaned off the inspection covers pretty well. Here’s the payoff. Not perfect, but much-improved.