Eibach pro-kit drop height differences

[JoeyBones]

I have a 91 318is.... there isn't a kit listed on the site for my car.

Moving to the 325, there are kits (i realize spring rates will be higher)

pre-86 they drop 1.6/1.4 f/r part# 2003.140
86-91 they drop 1.7/.8 f/r part# 2010.140


what gives here? I'd prefer the drop heights of the pre-86 i think unless there is a difference in the suspension that would throw this off...

[brandonj1]

this is mine its an 87. if you are interest i may be able to sell you my pro springs when i get coils some time soon

[JoeyBones]

well i'm possibly needing them like now, but want to understand why the difference. The later model heights seem retarded, unless its due to a mount issue.