You don't need a Tee to put the vacuum pump on.
If it's all on turns then there might be something going on in the tank causing starving and not even related to the rich problem. It just takes a few minutes to take the pump out and have a look at what's going on and get a look at the fuel sender problem while you're there. Having trouble installing the pump increases the chance something went wrong.
To take the pump out lift the seat bottom and tilt it ahead, stand it upright in the foot well and there is tons of room, no need to take off seat belts, cut a square of the sound proof material away over the pump if you haven't already, take the cover off, pry off the hose with a bit of care, the nipple has a metal tube but it's still plastic
use a small prybar and hammer to tap the retaining ring working a bit at a time on opposite sides. Really shouldn't take long at all.