Is the attached extract from eLearn, what you are seeking? 6.9dANm or approximately 70Nm. Have you got a suitable crows foot spanner? Please note that a 2005 Ducato will be an x244 model. (See VIN)
All my 2012 Autodata manual gives is Track rod end outer, sorry.
So you are back to the old mechanics answer to the question how tight? :- "strip the threads and back half a turn!!!" JOKE