a slither of high density foam is what you need so that it acts as a seal between the rad and intercooler. gaps are no good as the airflow takes the path of least resistance which ISNT through the rad if there are any gaps.you can have the best cooling equipment in the world but it will ony be efficient if its fitted in such a way that allows it to be efficient
rog, have you defintly eliminated head gasket/water pump condition and that the head isn't cracked? id be looking at a blocakage/severe air pocket or a tired water pump.