Q regarding leveling with one lvl80 and 4 70s

[Biz]

I know this has been posted before but I can't find it for the life of me. I have a hunter at 80, 72 druid, and 3 70s. At what level could I run an instance without the hunter crushing my xp?

[Ken]

If I recall correctly, the level difference with your highest level character can be maximum 5 levels, but I tried to Google it and can't find any data to back this up, so correct me if I'm wrong.

[Bloodcloud]

wowwiki: http://www.wowwiki.com/Formulas:Mob_XP

cheers
Blood