Slant 6 cylinder Aluminium engine

That Kanter gasket kit is not a bad deal, though I agree the description to 1983 sounds strange. Read on www.slantsix.org about how the head gasket for the aluminum engines were unobtanium a few years ago, so some got together and made a group buy of custom copper head gaskets. They might have paid >$100 just for the head gasket.

The group buy of copper gaskets, was not for the aluminum engines. It was for power added iron engines. I do not think a solid copper gasket would work on an aluminum engine. As far as I know, Kanter has always had the aluminum engine gaskets available, although they have raised the price a few times.