Need help with getting correct fitment!

Hello guys! I need some help with getting a right fitment for my 17 Mustang GT. I recently purchased new wheels and tires and the specs are 255 front and 285 rear. I am sure those wheels and tires are going to fit, but the problem is future modifications. After driving for several months, I am thinking of changing my rear tires to 305. I am also thinking of getting 1inch front and 1.5 inch rear wheel spacers and about 1-1.5 drop for lowering springs. If I change the tires in the future for 305 sizes, will it hit my fenders? and will it fine to get spacers and lowering springs with 255 and 285 specs?
Thank you!

You should start in the correct section: http://www.mustang6g.com/forums/forumdisplay.php?f=65


The most important piece of information to answer your question is the specs of your wheels, mainly width and offset. Tire width doesn't help much as many people have much wider tires than what you're thinking of.

Thank you. I will repost at the corect section. Do you know how to delete the thread?
Sorry I am new to this forum and have a lot to learn.