I don't know what "front runners" are, but you can measure the backspacing of your current rims. The "backspacing" is the horizontal distance from where your rims are attached to the rotor, to the backmost part of the rim flange.
For example, I measured the backspacing of my stock 17x8 rims, and it was approximately 6.5 inches.
You might want to get a 2nd and 3rd opinion, though. And, again, be sure to measure it yourself.