Thanks Stuart,
The factory changed to the aluminium gaskets around 79.
This would be about the time of 350 electric start introduction and other engine changes
The blue manual published 1979 I think, clearly shows aluminium gaskets being used.
and in use on earlier engines, which is fine, if you use the sealant.
Athena list the gasket 1974-1978.
http://www.athenaparts.com/eng/products ... ead-gasket
I have 2 engines of the 14XXX range that are from 78 with the stepped liner.
Mark