I've been reading through past posts for about three hours now, and i still have not seen the answer. So here goes:
19x9.5....+30
19x10.5...+24
Can i run 255/35/19 & 285/35/19 w/ less than a 1in. drop w/out rubbing?
I have called every body shop in my area about fender rolling and none of them do it.

 

If im not mistaken, you can run 21mm in the fron w/o rubbing..i know a 245 is np..

 

You will rub in the rear with a 285/35 in that offset. Getting a 30 series sidewall will help

 

I have 20x9.5 25 offset on the back with 275 tire and no rub at all, even room to spare on a .6 drop. If you have an issue I would be surprised but at most will need to just roll the fender slightly.

 

Whoa, I have the same exact wheel setup as you, except I have 295/30/19 in the rear. I put them on a friends Z that is dropped with springs about an inch, maybe more, and they didn't rub at all, even over nasty speed bumps. But, he also has his fenders cut...