Actual Wheel Backspace

[Hard Luck]

I have a 69 C10 with 2.5" drop 12" disc brakes. Stock upper and lower arms with a spring drop of about 2". I ordered 17" x 8" wheels and they came in with a 3.625" backspace. It was too far out up front and I couldn't get 2 miles down the road without massive scrapping in the wheel well not to mention that they did not look great.

We took a few more measurments and came up with a 4.875" backspace on the same 17" x 8" wheel. Before I reorder (another 6 weeks) hoping to find some good solid information.

I would like to find out what the best backspace is on these trucks.

I would also like to hear what backspace you used with a picture of how it looks in the fenderwell. I am looking for guys with stock style suspension (no air bags) and stock inner fenders (no tubs). Thanks gang!

Backspace is measured from the mounting flange of the inside of the wheel to the inner wheel edge (not the lip/ or last step in the rim)

[andrewmp6]

You know they make a tool called a wheelrite that lets you test fit any rim size and back spacing.Here it is http://www.summitracing.com/parts/PHP-01201/

[502ms]

That's a great tool, Andrew.

Mr. Luck, you said no bagged, but I'm running an 8" wide smoothie, and all up the range from on the ground up to C10 stock ride height, no problems. Backspace of 4.25 . I am using the OEM UCA/LCA with a dropped spindle, mild Z and airbags. Lays frame.
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[lolife99]

Go with a 5" backspace on a 17x8 wheel up front.

[mixermike]

Would you be interested in running 18's and 20's ? You could come over to my place and check out my wheels on my truck with a 5 1/2" drop in front and 7 1/2" drop in the rear. I would like to sell them and run 20's front and rear
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[gringoloco]

4.75 to 5 on an 8" wheel up front. 5.25 on an 8.5". These are tried and true numbers that are often used by members here on the boards. Your measurement sounds spot on...
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[Hard Luck]

Thanks for all the input. I ordered a 4" backspace (based on the centered offest of the current wheel0 but they came in at 3.625" Just worried about going in too deep. Have been considering doing a 17" x 7" with 4.5" backspace just to avoid problems. I was hoping to run the same wheel and tire all the way around to carry one full size spare and rotate the wheels but no go. Tire size is 245/70/17 I will go narrower up front if needed, that can be changed but the wheel will not be able to.

Originally Posted by mixermike

Would you be interested in running 18's and 20's ? You could come over to my place and check out my wheels on my truck with a 5 1/2" drop in front and 7 1/2" drop in the rear. I would like to sell them and run 20's front and rear
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Hey Mike, I would love to come up and check things out, see how your truck is set up, but as far as the wheels go I already bought my wheels and 18" or 20" are more of a mordern look than I was trying for on my truck. Let me know. Thanks.

[mixermike]

Anytime brother
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[Hard Luck]

Went and checked out MixerMike's collection. (Thanks Mike, nice to hang out with you for a bit) He is running 18x8.5 with 5" backspace. I am leaning towards 17x7 with 4.875" backspace. Mike brought up a good point that the face of the wheel might be too far in the fender and look goofy. Does this sound right? About ready to reorder and wait the 6 weeks again.

Speaking of looking goofy. Here is the first mounting of the 3.625 B/S wheels.