Your best bet is to contact David Diesel Development and see if they can machine up a diesel head for you. They may already have the specs for your engine and can whip one up right away. You basically only need a diesel head for your engine and you'll need to replace the fuel lines with diesel proof lines.
http://davisdieseldevelopment.com/home.php
They are the center of the universe for modern diesel engines and conversions.
Unfortunately you would need a way to machine a new head with a contra piston in it. You cannot do that using a dremel. You would at least need a lathe to do it with. A milling machine would be a plus too.