This may sound like a dumb question but will the KMC Rockstar 20"/10" rim fit in a Toyo Open Country M/T 37"/13.5"/20" tire? I'm a little confused about the width of the tire and width of the rim. Do they affect eachother in any way? Also, I don't quite understand what backspacing and all that is. On my previous truck I told the guy what I wanted and got it all done. This time around I want to know my stuff.