340 engine serial number decode

as the model year started before the calendar year ended. So it could likely be cast the previous year. 3 to 6 months from what I have seen is typical from cast to assembly to assigned to a car. The above example is about 3 months.



da4ad said
Just to clarify using the following #'s
340 Block
Casting # Right side 1-27-71.................. Date forged/cast (Jan 27, 1971).

YES

Casting # left side 2780930-340-5........... Part #.

Casting number the -5 is a mold revision number from the original mold after x amount of revisions molds are replaced.

Pass Side # 1B365483............................Last eight digits of car serial #.

close. the 1 = 1971 model year of vehicle, B = car assembly factory in this case B = Hamtramck, last 6 of car VIN.

Front Left # GM 340P 35460007..............Date machined (April, 13 1971).
So for instance a 1973 car could have a 1972 block?

YES

please correct me if I'm wrong as i am trying to find a correct date coded motor for my car.
Click to expand...

yes need to know the build date of the car. but a 73 model vin block will start with a 3 even if casting date is 72