I already added 3" to the rear WB. the arches over the rear is the appropriate size for fitting something more serious than your average 225SR50 HP Radial, if ever the need for such exercise might show itself.
The 195-50 15” rubber you see there now, is high end budget, at best…. I’m aiming for at least 18” rims to be the Std… My wallet thinks otherwise though
a Link to where I have some pictures for poeple to look at....