I have the almost identical gauge in my car right now, But as my 2.8 doesn't have any options to hook it in, I will need to get myself the same type of fitting. On the 4.2 you could put it into the bleeder at the top of the thermostat housing, If unsure what I mean read this in my thread as we are talking about it at the moment!

http://www.nissanpatrol.com.au/forum...l=1#post443163

Cheers,
Eric.