Originally Posted by NWRQC
To answer your question. If you are keeping the same wheels and want the wheels/tires to fit the same (stick out) as they do without the flares then you will need to measure how much the flares stick out from the fender then add a spacer that's the same width. If your flares are 2" then you will need 2" spacers, 2.5" flares = 2.5" spacer and so on.
To add to this and correctly clear this up, it is wheel adapters you seek vs spacers.
If you go this route, make sure it is hub centric and if possible wheel centric, but this isn't necessary as you can always put wheel hub rings on.
I still would not go this route. Too much strain on your stock components and also the possibility of rubbing which will require some trimming
Originally Posted by chadster21
i don't think a 2.5'' spacer is a good idea.... an offset wheel would be the best bet
What he ^^ said