Here are the photos. There are also some markings on the pan rail as shown.
There is a lot of rust in the water jackets so I'm having doubts if this block is good. I'll get it tanked and thickness checked. We'll see.



'55 T-Bird
Battle Ground, WA

Finding rust in the water jackets is not uncommon; that, alone, is not indicative of the block being bad. The rust, of course, will have to be removed, as it's a common cause of overheating. 

The dot between the 0 and the 1 makes more sense with the picture.  That’s the screw head that holds the date plate to the mold during the casting process.  Based on the picture that’s provided, I’ll go with the date code being 501.  That is expected to make the casting date October 1, 1955.  After that point, it went through the machining process before actually being assembled as an engine on Oct 19, 1955 assuming that stamped date for the assembly is not being misread.  If this engine is original to the car that it came out of, then the production date on the car should be shortly after the engine assembly date.  That information will be on the VIN data plate on the car.

The various stampings on the bottom pan rail are likely just inspector stamps for when various operations were performed to the block during the machining operation.

Any other thoughts on any of this is welcome.

Lorena, Texas (South of Waco)

Just to ad to this, My '57 date coded block had a cross drilled cam in it also. 292 out of a '57 T-bird.