overload helper springs

[bonnieclyde100]

1 purchased a set of used helper springs the ones for the coil springs with trailing arms but did not get the plates that come off the trailing arms that they come in contact with. my question is do the helpers hang above the trailing arms and only contact with loads in the bed or are the springs preloaded at all times? also if they hang above what is the distance from the spring to the plate. my truck is lowered a bit and i will have to make my own plates.