I say you'll be ok, but it all depends on what terrain your driving on. Rocks are alot more punishing. Peterson's has a good article in the Jan issue about axle strengths.
I know of a few guys around here running tires about that big...
XJ, HP30, ran 36 SXs for a while, now 38 TSLs. It's open... and wheeled pretty hard. I know he broke a few u joints with the 36s, but they were the 260s if I remember correctly.
ZJ, HP D30, Q78 TSL,4.6L stroker. Balls to the wall wheeling. Broke a 260 u joint on an ARBed LP30 with 33s, with the Qs and open HP30 no breakage I know of.
TJ, LP30 open, 36 TSLs... no breakage.
CJ7, Ox locked LP30, 36TSLs and chains... broke U joint.