Slant 6 cylinder Aluminium engine

Hi im new on this forum, and the owner of 2 Valiant -64 Wagons.
Please excuse my bad english, but ill hope yuoll understand

The car, have a aluminium engine and i need the cylinder head gasket, seems to be hard to find, it would be nice to get some help.

Regards from a sunny Sweden, and thanks for a great forum.
Michael