Piper, apologies, my 'tomorrow' became a week!
Studs are M8 on as good as 28mm centres, maybe 28.25.
Standard M8 thread pitch whatever it is , it isnt fine.
Studs project out 40mm, or atleast that is a nice figure. The pair I measured were 39 ish.
I only have a GT3 Cup bushing here to measure, so the other dim you need...centre of bushing to flat face..isnt really what you want for road car control arms.
I measure 55.0mm, and from some measurements against a standard (non adjustable arm), I would think this is atleast 10mm more that the regular street GT3 adjstable arm.
To concur this and also that Porsche used the same casting for street and race, ans just machined more off the street versions...the holes in the Cup bushings for the M8 are 27.5mm deep yet the stud ony inserts 13.5mm....so the hole is deep enough for the street version when more metal from the face is removed.......hope that made sense.
I include a photo here to show you the Cup inner bushing versus the street....I had both version to hand a while ago....not now unfortunately.
ignore the shim...check how much ally is in the cup bush compared with the street