Vacuum diagram 2.5L 1998
 

I have a vacuum tube T on the passenger side below the air box . Does anyone know where it goes to?

that wouldn't be the EGR would it?

The only T I see on the diagram is one that goes from the vacuum reserve tank under the passenger side fender and the 4X4 hub solenoids and the line that goes into the cab for the heat/air box.
Dave

The truck is 2WD ,one end might go into the fender (probably the vac tank ).Maybe one end should be capped as it might be intended for the hubs on 4WD ? Where do I find a diagram? The one on the rad cradle is little help.

You should have one under the hood on the radiator support.