so i got a set of coupe eibach prokit springs, i know that if i put on 350z springs it will be 1" lower then the stated drop for a 350z on a sedan, is it the same deal with a coupe except 1/2" more of a drop on my 03 sedan?

 

Yes.

 

so yes it will drop it 1/2" more then that stated drop 1.1"f 1.0"r, so i will be getting approximately a 1.6"f and 1.5"r drop?

 

Yessiree.