SS springs & sliders...
Well they look just like the AFCO sliders I use on my Duster with a set of AFCO leafs. Except those are about half the price of the AFCO's. Being speedway I'm sure they're made overseas, but that doesn't necessarily mean they won't work. Pretty simple pieces really, just an axle that runs on some bearings in a track.
Now the leafs I run are zero arch, but again, I don't see how that would be a big difference to the SS springs. You might want the static point of the rear eye to be a little further forward so it doesn't hit the end of the track as the springs compress because they can elongate more than the zero arch springs because they're almost flat at ride height but that's about it.
@younggun2.0 runs a set of sliders, not sure if he has SS springs or not...