The casting numbers and date codes indicate that this engine was created July 13, 1965. It is a 225 and most likely it was installed into a D100 with a manual transmission. It has been rebuilt at least once with a .060 overbore. The engine had a bad carburetor with all of the plugs black and sooty. The oil rings were "stuck" and it mostly likely smoked. Somebody performed a recent tune up.
To know more, I would have to mount it onto an engine stand and tear it done more, and I dont have time to do that now. But I suspect that the head gasket failed. It is a the steel one and there is no coating on the surface.
