Having scoured and searched to no avail, I come here in search of some very specific information. I have, as the subject line suggests, a 1992 SE trim 240SX with what I gather is the optional "handling package" that was offered. It has the Super HICAS (and it appears to be the original unit), and the chassis plate has RKMS13 in the "Type" field. The springs the handling package brought to the table in the SE had a spring rate of 2.2kg/mm (123lb/in) instead of the 2.0kg/mm (112lb/in) of the standard springs. The main issue I'm having is finding any other specs about those 2.2kg/mm springs; wire diameter, coil outer diameter, free length, that's all somewhere in the nebulous expanse that I can't seem to find. Sure, I could move to other springs from some of the available offerings, though I'm looking at restoring rather than modding it. Most surprising is that the FSM only shows the softer 2.0kg/mm springs on FA-17 and RA-26.

If I can get a lead to what those specifications are, or the specifications outright, I might be able to order some springs for this old girl.

Would it not be easier just to replace the entire strut unit with coils rather than just the coils?
You could also take out your current springs and measure them.

Also I used to work parts at a Nissan dealership, I don't recall the springs being different from a non hicas car.