Hmm, that could raise alot of issues...
1 - Offset...+38 isn't that much considering stockers are +48. In the front it may be ok, but it'll rub the most on the front passenger side of the wheel well. In the rear you'll be S.O.L....that thing will rub like hell, no doubt. Rolling the fenders might take care of that.
2 - Tire...if memory serves me correctly, the BFG's have a squared-off shoulder so this may present itself as a rubbing issue in conjuction with the offset.
3 - Rolling Diameter...profile is a percentage of width...which means that will mess with your rolling diameter...
Stock wheels are 245/45/17 which = a 25.68" rolling diameter
Your wheels are 245/35/18 which = a 26.76" rolling diameter
Speedo will be off and this will make tolerances much tighter.
4 - Ride quality...I'm guessing you were trying to stick with the 35 profile tires to try to salvage some sidewall, even so this setup may give you quite a stiff ride.
...more issues may appear also...damn our cars for being so picky when it comes to wheels

Right now, my car is sitting becuase I have to roll the fenders--alot--275/35/18 AZA Z-1's 40mm offset.