TOPIC:

Hello,
Does anyone know if a head from a 1977 Z650C will fit straight on to a 1980 Z650F1 ?
Not sure if the F1 still has its original  engine, the numbers on the F1 start with KZ650BE######,
The 1977C engine numbers start with KZ650BE######  ???
Any help appreciated ,
Thanks.

It should. And you lose the emission ports and can use the smooth valve cover. A KZ750 head have slightly bigger valves..

Yes, but vise versa a later HYVO cam chain head didn´t work on a earlier roller cam chain head (missing top idler sprocket mounts).

Yes, you would have to use the cams from the original head. I knew I was forgetting something....The rubber block of the later covers, wouldn't fit in the earlier valve cover would it?

The cylinder heads on the 1980 Kz750E1 still had the threaded bosses to install the top idler from the Kz650.
I don't remember what valve cover I had to use on the Kz750E1 head once I changed over to the Kz650 cam chain system. I think I used the 1979/1980 Kz650 valve cover.