Ok looking at some of what has been said, not sure if mine is normal but maybe I appear to have my tank sitting back a bit further than standard. I should highlight in my first reply I had a typo and typed 17 when should have been 16. They are Front Runner tanks supplied by Dolium in WA and I think Mulgo supplies them as well.
I am not home at present but I would say I have over 75mm gap between tyres and tank. Can measure when I get home if you remind me next Wednesday. I know I can get my hand in a fist in between horizontally easily. I am fairly sure I gained a lot more than 5mm over what they showed when fitting mine too.
I would say you would get 33" tyres without too many dramas and I am sure there was previous discussion here with people having done so, with minimal rubbing on full compression of the suspension.
I am also happy if you know anyone near me that wants to put their 33" tyre on to check clearances. I don't have any 285/75R16s to try.
Running 235/85R/16s I have never had it rub or even come close. I reckon even with my 50mm lift it would it would hit the flare before it would even go close to the tank.
Having said that you would need to know the gap at full compression of the spring, not sitting normally in the driveway.
There is only around 25mm or an inch difference between mine and 33" obviously.
235/85R/16 Rolling Dia 774.6mm or approx. 32"
235/85R/17 Rolling Dia 800mm approx. 33"
255/85R/16 Rolling Dia 805.9mm approx. 33"
285/75R/16 Rolling Dia 800mm approx. 33"
35" Rolling Dia 825.4 approx.
35"s would be an unlikely fit and would certainly rub, but you may get away with 33"s.
depending on what you do you may need to think about trimming flares and guards anyway.
These could all be +- 5% depending on tread as well.