Okay guys, I've been researching this for the past two hours with probably pages full of google searches.

I just need to figure this out, its kind of simple. I just want to know if the B18A1 in my 1992 Integra LS is the same one that came in from the factory.
From what I've seen, someone said something about if the 7 digit code under the B18A1 stamp starts with a 3, its from 1993, 2, 1992 etc.
Mine starts with a 3, so if that statement is true would that mean my motor is out of a 93? Not sure though because I never saw anyone else mention the correlation there.
I know the dial thingy on the head shows the year, on the far left, and mine says 91. So kind of confused considering its a 92. So does this number correlate with the year of the car or just the year it was made?
If anyone can tell me that would be great, my car has 225k miles, so if this is true my engine isn't the same one, then this motor could potentially have less miles which is good
Again my engine 7 digit code starts with a 3, and my head is a PR4-4 and the year says 91.

Thank you!