I pulled a 283 out of a car 25 years ago that had been regularly driven up to the day I pulled the motor. I drained the cooling system but left the oil in it. Then engine was stored in a dry shed and although the carburetor had been removed the intake was covered the entire time.

We pulled it out of the shed a couple of months ago to rebuild it. When I got the valve covers off the tops of the heads didn’t look too bad. On tear down I found the oil had turned into a gooey blob in the pan almost like a thick grease (when I turned the pan upside down it stayed stuck to the sump in the pan and had to be scraped out). The oil passages were also plugged with the same goo that had once been oil and although I never checked I suspect the pushrods were too.

The engine still turned over easily but when I got the heads off several of the cylinders had surface rust in them and when I got the pistons out 2 of them had badly stuck rings.

I was actually pretty surprised, I had always thought if I wanted I could just throw a carburetor back on and run it…….I’m glad I never tried.

I think if I were in your situation I would at least do a partial tear down (pan and heads) and see what things look like. Just my 2 cents.

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