I know what went wrong.. I looked up the torques in my workshop manual, which showed for "Pontiac 70 lb". "Tempest" would be "50 lb". I read that as Tempest 50, al other Pontiacs 70... See the first attached pic. In Vickys link it showed 50, see the second attached pic.
Beware! It is a bit confusing if you ask me!
A-arm has been replaced and all bolts have been torqued last night.
Next up are the wheel bearings. Any tips & tricks on wheel bearing replacement...?