Our trucks come with high positive offset, so yes less positive is going to stick them out, but negative would make it stick out a lot. It will also do horrible things to the scrub radius. Not necessarily important if looks is the priority, and you like the look of wheels sticking out past the body.
As for re-gearing. The 285/60/18 would be fine on the stock gears, it is a 31" tire so smaller then the Pro4X factory wheel size. The 315/70/16 is an odd size but a 315/75/16 is a 35" and would really benefit from re-gearing. If going with a 315 you will want to go with a negative offset rim so that they rub less on the frame when turning.
As for re-gearing. The 285/60/18 would be fine on the stock gears, it is a 31" tire so smaller then the Pro4X factory wheel size. The 315/70/16 is an odd size but a 315/75/16 is a 35" and would really benefit from re-gearing. If going with a 315 you will want to go with a negative offset rim so that they rub less on the frame when turning.
