Older post, but no one answered so
Howdy and welcome from Northern Iowa
On stock A-arms, the biggest you can go is a 28".
Have read about a few owners say their 28's rub at full compression and max turning.
I have not had my 28's rub, but I have never been in the above scenario.
SuperATV has good Honda Pioneer 1000 high clearance forward A-Arms
Those that I linked to, the specs say 2" lift and max tire size of 31".
Have a good day