Date coding explained

[HK1837]

the 4 253 i have here are : 12J3, 18J8, 16G2, 31A9. I think i still have one or maybe two in the back of my dads shed.

how does the coding and numbering system work. how do you match one to your cars manuf date??

I'd like to see a 16G2 on a red engine!

As before trying to match cast dates is really a folly. You are much better off trying to match engines numbers with cars around it or match your original engine number as close as possible.