Most 1/8 GT cars (which are based on 1/8 buggies) are going to have track widths of 305-307mm.
The Slash 4x4 has a track width of 296mm, so when using 1/8 GT bodies the Slash's wheels do not fill out the wheel wells.
Hot Racing offers 17mm hubs for the Slash with +6mm offset, which would...