Yes.
Absolutely.
Perfectly.
Unless of course your 31x10.5's are 31x10.5/16's, etc.
Other than the tires not being 15", you are golden.
No problem at all.
They will fit.

_________________________
- TJ
2001 Xterra '03 VG33, SE 5 spd, 305/70/16's, Revolvers, UBSkidderz, Doubled AAL's, 3"SL/2"BL, winch/bumpers, skids, sliders, OBA, Snorkel, pine stripes....
Friends don't let friends drive stock.
http://www.gifsoup.com/view/501230/tj-tackling-crawlers-ridge-o.gif