I would think that the Moto Metals would have better spacing on them already. I rarely see anybody running aftermarket rims with spacers. I'm running 1.5" Spidertrax with my stock rims (6.25" backspacing) and BFG All-Terrain 265-70-17's. With the spacers, I have the equivalent of 4.75" backspacing & that's more than enough room. But I still had to perform the pinch weld mod to keep from rubbing during tight turns. Spacers actually make the pinch weld contact worse. If you can, just measure what you have now, get measurements on the specific tires you wanna roll with, & see if you even need spacing. Overall, you're probably looking at 1/2" taller and about 1/3" wider.