340 mopar intake issue
I have seen some performance applications run a type of thermostat spacer that raises the water outlet up. These could also be drilled for bypass and temp gauge fittings I would expect. Watch for interferience with the carb and air cleaner base.
Here is a link to a Moroso listing to give you an idea (Only found Chevy on the list however).
http://www.moroso.com/catalog/categorydisplay.asp?catcode=29400