is fuel return line to filter nessary or can it be removed

as the title says, can this be removed .it looks like another air leak site. and if removed what was used to plug nipple on injector fitting. also can return line to ip be done away with. pics would be nice

I dont know if it can or not...but I woulnd't get rid of it. Thats just my personal preference though.

Injection pump needs return.
The fuel filter does not.
Think of the filter line as a wanna be air bleed. They did that in 94-97, as well as the 6.0 in 03-07.
The feed should have nothing to due with bypass(return)
To block the injection line off at injector, I used to always use a extra return banjo from another cylinder.
If I still had all my webshots photos I could shoot some pictures over of what I used to build for these as well as what what was needed to simply remove the bleed in a clean way.