How much should I drop the front and/or rear?

[gotyorgoat]

I need some help to dial in the stance on my 67 Lemans. I have 18" wheels and the gap makes it look a little off. I think that I have enough offset on my wheels but I'm not sure how much I can lower the front before they rub when turning. I would use lowering springs or cut the coils to accomplish this.

Should I....

Drop the back 1" and the front 2"
Leave the back and drop the front 1"
Drop the front1" and back 1"
???



Thanks.