injection line ?
 

just did my DV seals and couldnt help but notice the #3 line (middle) is larger then the rest. the nut was a 17mm on the pump and injector side. all others were smaller tubes and 14mm nuts. is this normal? is it a balance thing or what.

603.961

thanks for info

When one of the Fuel Injection Hard Lines on my Volvo Diesel developed a pin hole in it I had another Line made at a Fuel Injection Shop.
The normal size of the line Nuts is 17mm. The one they made for me has 5/8" nuts on it.
So, from your description it may be that odd line is a replacement like mine is.

that sounds like a line from a 616/617 motor... I did not know they would fit...

Sounds like an injector/line/and delivery valve holder from a 65/6/7 would be the only way things would work!