You "T" into the pressure line by cutting it and reconnecting the cut hose with a three way fitting. I used a rubber three way vacuum fitting from a junker. Since 2 of the three openings will be occupied by the original pressure line, use the third one to send pressure to the guage. The pressure line comes from the back end of the intake manifold. Its about 3/16" in diameter and is supposed to be clear but is probably filled with soot and looks black. I took more time trying to mount the guage in a visible place than the actual plumbing. Good luck.

__________________
2001 Dodge Ram 2500 Cummins Turbo Diesel - 4x4, auto, 3.54 gears, long bed
-------------------------------------
'92 300D 2.5 Turbodiesel - sold
'83 300D Turbodiesel - 4 speed manual/2.88 diff - sold
'87 300D Turbodiesel - sold
'82 300D Turbodiesel - sold