I found a spot that should work: Inside face of the passenger seat box. I think this thing is larger than what most people are putting into their trucks. It hangs down past the frame if I put it anyplace on the frame. The back of the rear outrigger almost worked, but the piping was going the wrong direction. As it is now it is away from heat, spinning tires, up away from most mud splashes, and is easy enough to reach to drain when it needs it.
So far, I have the old system torn out, sedimenter in place, and the line run from the sedimenter to the lift pump. I get the parts tomorrow, and hope to have it done by the end of the week.