Serial and model year

In some way have my car model year -90. But my serial are K004698. That means after the PR 1132, year '88. Does anyone know if I read wrong ?

I understood that the MOD number that you get from the table in the parts catalogue was the model-year rather than year of manufacture and it seems that every year there were new modifications.

My GTA is a 1990 but looking up the K number gives me a MOD 8906, which suggests a 1989. It has the later engine (as far as I can tell) with the double fuel-pressure regulators etc.

Hope this helps

Jon