need guidance on wheels

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i have a set of 16X8 black steel wheels with 4.00" back spaceing and -12.00mm off set. i would like to throw a set of 265's all terrains on them as a spare set. how much will the stick out of my fenders? does anyone have these on there truck and could post pics for a reference?id like them to stick out alittle but if they stick out a mile ill just sell them and not waste the money buying tires for them...what should i do?