Change tag axle ride height?

[tree98]

I have a truck with a pusher and a tag. The down bags on the pusher are mounted right up against the frame like this   

The down bags on the tag have a 3" spacer between them and the frame, like this   

Does anyone know why the tag has a spacer like that? I would like to take it out and gain 3" of ground clearance when it's up so it's easier to back up hills. As you can see the tag is pretty far behind the drives so it doesn't take much of a hill to be a real problem.    and yes they are both the same make and model axle.