just answered the same question on the other forum
, edited here for relevance:
Okay, I did quite a fair wack of research on this same subject when I decided to go with a 2"RC lift. I first went down the design patch of wheel spacers to see what I can fit in with stock wheels, and whether pinchweld would be considered or not, and if trimming the upper control arm bolt will be needed (this is also a consideration when going for bigger tires). I was at first against all these mods, I am still against trimming the bolt, its not a good idea (when you want to remove the UCA later).
After many days of thinking about this, and some solid advice from friends in the motor sport industries, I was strongly advised against wheel spacers. They are designed for wheeling and motor sports, and not recommended for road use. One of the best manufactures of spacers, Spidertrax, states on the box "Off Road Only", so that fits into the same argument I guess. Imagine if one cracks at high speed, loosing a tire is one thing, loosing a wheel is another!... secondly unless they are 100% perfectly hub centric (ie machined flush to fit 71.5mm dis), you will end up with some wheel vibration, if you do a lot of mileage this will become irritating very quickly (let alone reduce the life span of your tires). Given you intend on driving on the road 100% of the time, I would recommend investing in a new set of wheels (safer and better)!. On the subject of vibration then, you will have to use hub rings to centre the new wheels on the hubs to ensure no vibration with a non stock set of rims (if you decided to go down this route). your stock hub dia is 71.5mm, and the second measurement will be dependent on the wheels you get.
The biggest problem I had was clearing the bolt; my '09 had less than 0.5" between the stock tire and the bolt!. I needed rims that would move a larger size tire away from the fender to clear the bolt. I don't mind the tires sticking out from the fender as i prefer the aggressive stance. I calculated any rim with a 0mm up to -12mm offset would do this, as long as there is about 4.75" of backspace to clear the callipers. I went with Pro-comp rims (17x9).
I did not get any rubbing using 265/65/17 A/T tires, but still decided to do the pinchweld mod as I plan on running bigger tires in the future. The reason I went with this size tire was to fit a 9inch wide wheel, as 265/70/17 are rated to wheels that are up to 8.5 inches wide. the next size up will be a 285 .. maybe with an SL one day
choosing the new wheels option means you can control the position of the tire without using spacers ... safer, and you have a spare set of stock wheels you can sell to cover the cost
Here are some pictures for your reference:
PS - the rig also has Bilstein HDs all round, BWoody sway links and a few other mods