"Smooth" is a relative term.  Smooth according to what standard.  I beleive
what they refer to smooth as compared to a standard 2" lift which is harder
riding than the 2" smooth lift.  I had a 1976 jeep with a "soft" suspension.
It was soft compared to a 1967 Jeep which had no give at all.  Mine rode
like a Cadillac compared to theirs, but still rode like a rock compared to
my car.  My stock springs were worn out on my 84 and bounced like hell out
of control.  The smooth lift made the ride smoother than a standard lift,
but stiffened the truck back to a factory kind of feel where it got the
bumps over with in a hurry.  I don't like to bounce.  I don't beleive you
will ever be able to make an 85 4x4 Toyota ride as smooth as a new Toyota
with the coil springs, unless perhaps you reengineer the suspension to
handle coils or airbags and frankly, I wouldn't want to mess up the off-road
function of that truck.  Want a softer ride?  Buy a newer truck.