Oil pan/oil filler tube.

[Dwain G.]

Weasel engine?

I wondered about that also, but I think all weasel engine numbers started with a 'T'. Also, a photo in February '83 Turning Wheels shows a different style date code on a Weasel engine (5 8 45). Other Stude date codes always used a letter to represent year.

[Dwain G.]

Another possibility! This engine was produced in 1945 as a service replacement. It would have had no serial number stamped. A dealer installed this engine in an owner's 1940 Champion and as instructed by the factory, stamped the original engine number on that boss on the block. In many states cars were titled by engine number back then, so this was pretty important. It's possible this engine has cast iron pistons in it.