This is just slightly off-topic. My S14 engine block has the following on it:
23 4E A
According to the info that Ron posted, here's what it means:
003: Serial Number
093: Production Day
23: 2.3 L
4E: 4-cyl fuel injected
Anyway, what does Production Day mean? Day of the year? It was built in 1987, which wasn't a leap year, so day 93 would have been April 4. That doesn't exactly match the rough production date of my car, gathered from the VIN. Hmm..