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  1. #1

    Default backspacing for 20X9 w/2.25 level on '08

    Ok, I have searched the forums and I have found that I can run a 305/50/20 on a 20x9 with a 2.25" level kit, however I cant find a definitive answer for the backspacing and offset (which is confusing after looking at so many posts).

    I have a 08 Silverado Crew Cab, 2WD.

    Is anyone running this setup that can help me out? I have used the tire calcs. and I know the 305/50/20 is a 32x12.

    On a similiar note....does anyone think a 275/55 would look better under my setup or should I stay with the 305/50? According to the tire calcs., the 275/55 is only.05" smaller sidewall height, but is 1.2" narrower.

  2. #2

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    i'm running 285/65/18 on -12mm offset rims and a 3" suspension lift. only minor rubs on the plastic fender which went away after i trimmed it with scissors. a 305 size tire will definitely rub up front, especially with just a 2.25" leveling kit. many ppl have fit 33" tires (285) with leveling kits but rubs always a problem especially when you offset them. i wouldn't go higher than 285 unless you put a real lift on it.
    ROTARYENGINEPETE
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  3. #3

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    Interesting. According to the tire calculators, the 305/50/20 is a 32x12. Which in most of the posts I have read, people run 33 with minor trimming and a leveling kit. I assumed I would be good, I just wanted to make sure I have the proper backspacing.
    2008 Silverado Crew Cab 2WD
    2.25" leveling kit
    20x9 0mm offset MB 72s
    305/50/20 Nitto Terra Grapplers
    Line-X color matched Spray in bedliner

    2001 Camaro Z28
    Lots of Sh**......12.2 in 1/4 mile.


  4. #4

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    yeah, thats weird how the tire code works(the 305 is the width and the 50 is the aspect ratio). mine is a 33" tire, and yours would be a 32" tire. i'd be careful still as the width of the tire also comes into play not just the size, if it is really wide it can still rub. good luck though i hope it turns out looking great!

  5. #5

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    Thanks for the help!

  6. #6

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    It looks like after some more research and talking with a couple of guys on here that I should go with a 5.5" backspacing with a 18mm offset.

    Anyone disagree?

  7. #7
    Master Mechanic Burden33's Avatar
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    Default

    i got a 3" liift from rc and im running 20x9 iwth a 0mm offset wrapped in 305/50/r20 toyo at and they dont rub at all.





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  8. #8
    Master Mechanic Burden33's Avatar
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    Quote Originally Posted by rotaryenginepete View Post
    yeah, thats weird how the tire code works(the 305 is the width and the 50 is the aspect ratio). mine is a 33" tire, and yours would be a 32" tire. i'd be careful still as the width of the tire also comes into play not just the size, if it is really wide it can still rub. good luck though i hope it turns out looking great!
    305/55 is a 33" and 305/50 is a 32" so basically they are the sam

  9. #9

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    So if I have done my homework correctly, going from a +18 offset to a 0 offset, the wheel will stick out a little over a half inch more, which I would rather have. I didnt want the tucked in look.

    Thanks for the help Burden33! You pretty much gave me exactly what I was looking for.
    Last edited by bpaulk; 06-09-2010 at 12:53 PM.

  10. #10
    Master Mechanic Burden33's Avatar
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    no problem only here to help

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