I have a 2007 Chevy Avalanche LT 4x4 and im wanting to put a bigger tire on it.?

[ryanfuller_55]

I have a 2" front level kit on it right now with 18" rims already. Does anyone know what the biggest tire i can put on it that will be safe from rubbing? Its 4x4 so im wanting something like BFG Muds or BFG All-Terrains. The rims are 18x9