Help! Why is the 240Z this way?

[V8-240Z]

NISMO sells the following springs for the 240Z.
What is the reason the RF & LF are different
when the spring rates are the same?

Stage I:

54010-E4107 240Z Spring / RF (101 lb/in) 1ea
54010-E4106 240Z Spring / LF (101 lb/in) 1ea
55020-E4201 240Z Spring / R (112 lb/in) 2ea

Stage II :

54010-E8100 240Z Spring / RF (122 lb/in) 1ea
54010-E8101 240Z Spring / LF (122 lb/in) 1ea
55020-E8100 240Z Spring / R (140 lb/in) 2ea

Dave...

[Daniel]

I think it's to compensate for your hinny in the drivers seat. Daniel