Cylinder head casting codes

[rustyp]

Hello there, due to an unfortunate bodging by some unscrupulous Japanese exporters my engine is apart.

The head that came off my engine is virtually brand new (it is very shiny) and has a different code to one that my friend removed from a Bongo at his garage. Mine at first glance seems to have larger ports.

My head is code FL12
The other head is FL8

(due to the vagaries of my memory it may have been FLT8!! - certainly the other letters and number are correct!)

Is my head off a different possibly naturally aspirated engine variation?

Russ