Originally Posted by 02BlueStepside

Ok, trying to work this out with you...

With the 8.5 front and 35mm offset, I get a backspace of 6.1"
With the 10 rear and a 35mm offset, I get a backspace of 6.8"
With the 10 rear and a 75m offset, I get a backspace of 8.4"

Now, if you add in 1.25" adapters, you front essentially has 4.85" backspacing, and rear with 35mm has 5.55". Rear with 75mm has 7.2"

I ran 20x8s with a 5" backspacing and they were really close to flush. I did not have rolled or cut fenders (stepside bed). Here is a pic of how close mine were, and this is with a 245/40/20 tire



Your front will being a wider wheel, and less backspacing will be about .75" further out than mine. The rear 35mm, even with .5" extra backspacing, you are adding 2" of width, so they will stick out about 1.5" further than mine. The rear 75mm, will only stick out about .25" more

I believe my calculations are correct, I did them several times to be certain. With that said, I THINK you should be ok in the front, might have to run some neg camber to be sure, and the rear with only .25" difference should be fine with rolled lips.

With all of that said, why run a 10" wheel and a 275 tire? I ran 275s on my 8" wheels and liked the look better than if it was stretched. If you like the stretched look, so be it. Personally a 275 fits a 9" best IMO

Originally Posted by 1FastBrick

1.25 is less then 1.50 there for they would sit inward .25 more then the math done with 1.50. Not out ward

Your Truck looks good by the way!!! I may be biased though since my Silvy is the same color.... LOL

Originally Posted by 1FSTGMC

Ok so i wasnt to far off from what i figured too.

Now the reason im running those sizes is because with the wheel im looking at they only make paticular sizes from the particular bolt patterns. I choose the 5x120 bolt pattern because i couldnt find a large selection of adapters that were 1.25" thick with the 6 to 5 bolt pattern. Im sure there is a 6x139 to 5x112 out there somewhere thats 1.25 think, im sure i just havent found it yet.

Originally Posted by 02BlueStepside

Correct, but I thought he was using 1.5 and I calculated for 1.25. That would push the wheel further out, but like you said, from 1.5 to 1.25, the wheel sits inward...I must have mixed several post. I see 1.25, 1.5, and 2 lol. But it looks as if the spacer is 1.25" so the original post with math should be correct haha

And thanks for the complement! Blue wasn't my first choice...but I didn't have many choices for a reg cab stepside with a v8 at the time. I've grown to love it and wouldn't any other color now


I did realize after the post that 5x120 seems to be a much more common size, which makes sense that you can easily find those adapters. And like you said, I sure with enough searching, and money, you could find the 5x112. However, with the 1.25" spacer, I THINK it will just squeeze in there and you will be ok.