How do identify what year my engine is?

Don't know if it continued but drivers side, front of block, just under the head there might be a series of number letter stampings.

IIRC the first letter is the year. C was for 67 model year, D would be 68 etc

Some letters were not used (i, q maybe O oh not zero), the engine displacement is in there too.

Most likely easier to look for the casting marks especially if you have AC or PS