what do these engine numbers tell me?

[jar1292]

k the drivers side has the casting numbers 4006630-440-3
on the back there is a casting of AR
passenger side there is a casting of what it looks like to be a 2 11 75 and under that there is the numbers 4006630-440-3 again under that there is a clock with the arrow about in the 4 o clock position and to the left of that is what it appears to be two letters with an arrow pointing to the left letter? i cant really tell what they are.
the stamps by the intake read 5T 440 E
i think these are all the marking i could find although i didnt have much time to look it over. i know it is not the original motor cuz it was a 318 stock any info would be great.

[John_Kunkel]

4006630-440-3  is a common 440 block casting number, the -3 is a casting core revision number and 2 11 75 is the casting date February 11, 1975.

The arrow in the clock tell which "pour" in the work shift the block was cast and the other arrow will point to either D or N for Day or Night shift.

The 5T 440 E stamping is the build code which decodes

5= 1975
T= Engine built at the Trenton engine plant
440= Displacement
E= Cast crankshaft

There are usually additional digits stamped in the top pad to identify the build date.

[jar1292]

thanks john thats the info that im looking for. 

[troy.70R/T]

About that number that is the casting core revision. I have heard diffrent explinations on wht that number means. Can you clear that up for me or send me a link? Thanks Troy

[John_Kunkel]

The dash number behind the basic casting number is called the Casting Core Index Number, it is the number of core plugs that were replaced in the casting core that was used to make the disposable sand mold the block was cast from. The abrasive nature of sand makes the composite casting core wear and the individual sections of the core can be replaced without having to scrap the entire core.   

It is thought that a lower number is desireable because there is less chance of core shift from a virgin casting core but that's never been proven.