just recently got my 91 n/a z32 and found a problem the idiot who had it before me put over sized rotors and calipers on and put 10mm wheel spacers on it so everything would fit (after market rims 18 by 8 with a +45 off set all around) but didnt change the wheel studs so theres barely any threads holding the nuts on (found this out when replacing the wheel nuts because he only had 3 on each wheel) so my question is what size wheel studs should i get so that they will be long enough not to try to let go and kill me on hard cornering lol. also if anyone has any suggestions on nice looking cheep black rims of the same size i would be happy to listen because the front right rim is dented wheel shimmy from 60 mph to 75 mph

Ditch the spacers and try to find something with an offset closer to 35 (if you want to get the same sized rims).

i agree with finding the right offset but arp studs look sweet too

If there are no spacers on the calipers then they aren't oversized rotors. Get some stock wheels or wheels with the correct offset, not the cheap universal wheels.