as far as your speedo/odo q here's a link to the diablo predator programmer really easy to use to readjust for tire size just enter in original and new and your done instrucitons are a big help as well i just ordered 22's today and am either going to run 325's or if i can 37x13.5's maybe we can help each other out in this process
http://tsetruckstuff.com/Merchant2/merchant.mvc?Screen=...Product_Code=PDQ5151
oh and lemme know if you plan on ordering one too a buddy of mine got me a deal on mine and can probably get you the same price as well