I Think you will struggle. I have the 40' supermax with gooseneck in my Trafic SWB going down the left hand side of tank (resting on wheel arch) and it just barely fits.
The 44' might fit diagonally across the top of your tank but if not you can cut out a hole in the metal panel under the passenger seat so the pole lies from double back door of van, over wheel arch, through hole and into front cabin. Thats what Ionics did for me when I bought there 45' pole years ago. hope it makes sense.