In my life, I have never know
that there is a termination kit
to do this or insulated cable for 220 KV lines. It is too high and expensive.
It is to high and very expensive
to be insulated.

The only thing I could say is check
the IEEE guidelines and articles
on underground riser to overhead
high voltage lines. They have all
the information,even the drawings.
I know because I work before in a
power company in my country and
we used their bulletin and articles.

Check also companies that supply
the materials for this kind of
connection such as RAYCHEM and 3M.