If you want some kind of slammed ghetto-wagon, yeah, that will do it.

If you want to lower the car right, you need some quality springs/coilovers, some better shocks to keep up with those springs, and a camber kit to keep it all aligned right. And yes, it should all be done at the same time.

A 1.7" drop should not significantly alter the camber, but it would be nice to have a kit anyway for fine adjusments.