up size

I'm due for some new rubber and looking to up size my 33 Duratracs (275/70r18) to some of the new AT4Ws. I know 34s at 295/70r18 would be a slam dunk, but I'm tempted to go to 35s (285/75r18)- I see some folks saying 35s won't fit in the stock spare location so looking for some feedback on...