part number you need is 3627939c1 it is a 3/8 restricted fitting. Hope this helps it is from iknow article IK1200061:

Title: Low Coolant Light with International I6 EGR and MaxxForce® DT,9 and 10

Applies To: I-6 EGR and 2007 - 2009 MaxxForce® DT,9... Login to read more.