My narrowed P-30 front axle measures 59.5" center to center of tread (on 22.5" wheels/tires).
The rear P-30 axle measures 57" center to center of the inside dual wheels.
That's only a difference of 1.25" per side away from perfectly tracking in each others foot prints.
However, I narrowed that axle more than I should have (first installed in it the 1 ton) If I remember right it was about 1.625" to narrow per side than stock.
When I do it again I'll probably make it a little wider than stock, so the difference in front track to rear track width per side might be 3.25", or 6.5" total. That would make the center of the front tires track close to the outside edge of the tread on the inner rear duals. Or in other words only half way overlapping tread, and half way not.
Confusing enough?
I'm still not worried about it.
Grigg