Rear helper springs

[abunai12]

1999 extra cab, 2wd, 5speed
I noticed that when I carry any load, the rear sit low.
Has anyone tried helper springs????
I was thinking about air bags, but don't want to have to fill/remove air when needed.
Was also thinking about making my own helpers.
Maybe coil springs, cut to the right height, between the axle and frame.
Not to lift it, but just enough to help keep it level with a load in it.