Head gasket/sealing ring on 98mm Mahle cylinders?

[emcon5]

I am still progressinng with my rebuild, and am ready to install the heads. The 98mm Mahle cylinders I am using do not have a groove machined for a sealing ring.

Is there a gasket or something I am supposed to use between the cylinders and heads, or just slap them together and call it good?

Thanks,

Tom