if you significantly drop the front end, over 1/2". you will drastically change the front end geometry. and you should have the front end re aligned.
i dropped the front end on my 72 road runner 3/8" without really changing the toe, caster, or camber, out of specifications. if i remember correctly the camber is a little over 1/2* neg camber from almost 0*, 3* pos caster from 3 3/8 , and between 1/16" to 1/8" toe in from 1/16".
i get more tire wear from excessive pos caster than from the toe.
i dropped the suspension 1 1/2" - 2" from stock before i lowered it another 3/8".
after i dropped the front end i checked the alignment and didn't change a thing. i have driven this car over 15K miles and the tires still look like new. the tires are pirelli p-zero 17". i have to check the exact size, metric equivalent of a G 70, but they were take off tires off a 07 mustang gt.