Did a bunch of suspension stuff today for the 240Z.
Heights were wrong to begin with, as I suspected. 60mm lowered geometry! But the rest of the measurements were correct. Even the camber values at max droop as reported by the workshop manual is the same, so it's probably in the ballpark.
Also solved the mystery of the Euro Spec II springs height difference. Maybe I should post about it on some Z car forums, as people still post about it.
There is next to no height difference between USDM and EUDM suspension, when UNLOADED. EUDM rear is like, 1mm higher at most. This makes sense because the 240Z camber is for all intents and purposes un-adjustable, and if the car was indeed 1 inch lower as the brochure reported, the camber will go all out of whack.
When LOADED ie: 2x 68kg occupants as specified by Datsun, AND installed with the 1inch higher spring perch of the European front strut, when you calculate the heights from the loading of the occupants and the different wheel rates, the height difference compared to OEM which has been reported as being 0.9 inches down front (+ 1.0 inch up from the strut) and 0.4 inches up rear, it adds up! Nearly exactly. I suspect it's down to the dynamic motion ratio, slightly different CoG of the occupants etc.
Just some nerdy stuff for us number crunchers.