Here is some information
235 Engine ID Info I have a 53 passenger car motor. It has the same head casting number (3835913). On the other side of the head from the casting number I have a cast in B36 then 913, 241, and 570 stacked on top of each other. I think that the B36 means the head was cast on the second month (B) the 3rd day in 1956? B36. This would mean my motor was rebuilt with a different head.
I would be interested to see what numbers are cast into yours. See this link.
Head date??? I think from the first link above, yours was the 258501st block at that plant that year. They started with #1001. F means the Flint plant, 54 is the model year and X is the engine type. The table linked above has types for the 53 and older trucks. It looks like it only has data for 1954 cars. I guess that X is for a truck motor.
Here is where my block casting number is. The front lower passenger side just above the oil pan.
Block casting number Here is another picture of the new motor I am installing. It is a 57 motor. This is behind the starter and is the date code.
Date code In this case it was a November 21st, 1956 casting, which would have been put in a 1957 model truck.
You said yours had A 27 4. I would read this as January 27th, 1954 as your casting date.
I am not sure where I read it, but there are 2 screw heads. I believe these held the date plate on the form. In any event, somewhere I read that you can tell if it was cast 1st, 2nd, or third shift. For example, the first shift might have used 2 flat head screws, the second shift then use a flat and a round head with the third shift using two round heads. I am not sure which was which though.
Also, you can see on this 57 block that the beginning of the casting number is just forward of the distributor above the GM.
Hope this helps.
Also check out
www.inliners.org. They have some info about casting numbers as well.
