Thanks to the approximate length of the strut from ball joint to strut top (and I realise it varies with ride height!) on datsuns, I seem to recall it was very close to 1cm=1 degree of angle. This will work at small angles/changes in distance, which is the limit of what would be achieved here anyway, it certainly won't be accurate when you get out around 10-12 cm difference.

http://en.wikipedia.org/wiki/1_in_60_rule

It's not dead accurate but handy enough for guaging the approximate changes you might or already have achieved via moving strut tops or control arms or caster bars etc.