Gazpar,

I am assuming that is the number that is on top of the cylinder head (as in the casting)?

The actual honda part numbers are slightly different.

For RKII, the part numbers are 12210-KV3-000 (or 12210-KV3-010 for the front head and 12215-KV3-000 (or 12215-KV3-010) for the rear head.

Fo you have a RKI or an RKII (1988 vs 1989)?

Someone else may know the correlation between whats in the casting on the head VS the actual part number and be able to give you further details.