camber is not what kills tires. stretch isn't either - the ******* STOCK NISMO FROM THE FACTORY has a 285/35/19 on a 19x10.5 wheel. 10mm less is nothing
it is TOE being off
camber arms aren't fixing your problem
Solution:
Don't be a wimp
Throw away the crappy springs and camber arms you got on the car. I assume it's megan racing or some ebay brand of crap.
Get good coilovers
Get the SPL full setup
Get a proper wheel/tire combo
Take it to a performance place that does aftermarket suspension, preferably with experience on track cars and such
Slap all the parts on
Get an alignment. Camber as necessary to fit wheels, then minimal toe (if not zero outright)
Enjoy your Z that now looks and drives better and won't eat tires.
Read through THIS:
Wheel Fitment 101: START HERE