Need a favor for those with 18" Halibrands and IRS

[Brian76]

Another wheel offset and backspacing thread! We are planning to purchase 18" aftermarket mustang wheels for our MKIV w/ 2015+ IRS. Every wheel is different, so I'm trying to determine a range of offset and BS that will fit. Since Halibrands are the most popular and are made to fit our cobras, I thought I would use its offset and backspacing as a reference point.

What I need from this awesome community are measurements between your outer tire and inner fender and between your inner tire and suspension (or nearest component). Please see attached picture of what I'm looking for (I apologize for the crude powerpoint drawing).

106359

**If anyone has a easier method to confirm a tire & wheel combo will fit BEFORE buying...I'm all ears!!

[Railroad]

I got 3 5/8" between the shock and the rubber on the tire.
I have 18" Halibrands with BF Goodrich Rival S1s from Summit Racing 245/40/18s.
The tire width is 10".
I do not have the body on the car and my ride height is about 5".
Usually when someone answers, its like, "release the hounds", so you should be getting answers. Good luck,

[Brian76]

Thanks Railroad. I have a couple questions
1. Are your 245's for both front and rear?
2. Are you using 10" wheels on front and rear?

Still waiting for the hounds...lol

[Railroad]

315/30/18 on the rear. 18X11 Halibrands on the rear.

[Brian76]

315/30/18 on the rear. 18X11 Halibrands on the rear.

Thanks. What is the distance from shock to rubber on the rear?

[Railroad]

Thanks. What is the distance from shock to rubber on the rear?

3/4 to 7/8"