I forgot how to do this and instead of figuring it out, thought someone here can tell me in a nano-second. Please.

The number between the 10 and the HP2 is a 5.

The engine is in my '68 Coronet R/T

Thanks,

1968 440 high performance (magnum) assembled on 2nd shift. I think the 10 5 refers to October 5th but other people here will know.

& it should have a partial VIN stamping back by the oil pressure sending unit

Thanks, guys.

I am going to guess that the "D" stands for the model year, i.e. 1968 in this case.

I have a 1965 383 and the top line reads A 383 so I am guessing again that Chrysler started using the alphabet to stamp their blocks in model year 1965.

I also have a 1974(?) 440 and the top line of the stamping reads "6T440E". WTH does that mean?

6T440E

6 = 1976 model year
T = Trenton, MI engine plant
440 = displacement
E = cast crankshaft

is the '68 440HP original to your R/T? if not, can you share the VIN stamping?

Thanks again.

Turns out that I have a book by Chuck Senatore that has the answers in it. Duh me

I still haven't crawled under the car to check the VIN stamping on the block. Busy guy, ya know. Yah, right...