Just confirming before I pull the trigger....

[Knightfall]

I'm about to pull the trigger on some Mickey Thompson Classic Baja Lock Wheels, 17" size. Just trying to confirm some things before I buy something I'll regret. First, the bolt pattern IS 6x5.5 right? It's hard to find the answer and there are some conflicting sources....My second question is regarding the wheel offset. These wheels are -12, and are alot deeper than other ones I've looked at, most around zero and OEM wheels being around 27mm I just don't want the offset to become a huge issue with tire fitment. I WANT to be able to fit 285/70/17's on the truck, and my local shop (and other's I've asked) said I'll be fine, but if not I don't mind downgrading to 265's. However, I just don't want that deep offset to bite me in the butt with tire size. This is my first time ever changing the wheels on a truck, normally I just put mud terrains on stock rims and drive on, but I can't stand the big chrome 20's. My truck is completely stock suspension wise, btw.