Offset or Backspacing

[sjones24]

I bought a 1982 C-10 SHORTBED with 20x9 rims with a 18 offset on 275/45/20 tires. The previous owner installed 2.5 inch spacers to get the flush look in the rear which I really like. I want to order a new set of 20x9 rims and tires 275/45/20 for the rear without using spacers. Is there any way to use the 18 offset and 2.5 spacer numbers to calculate the correct offset or backspacing to KEEP the flush look? The front rims and tires are tucked in, which I also want to get the flush look as well. Anyone have any suggestions? Or send similar specs for what you may be using?

 

[Frankenchevy]

Is there any way to use the 18 offset and 2.5 spacer numbers to calculate the correct offset or backspacing to KEEP the flush look?

Yes

 

[Grit dog]

Just add or subtract 63.5mm from your current offset.
Moreso, do a little studying on offset and backspacing so that you understand it rather than asking for a magic answer.
And don’t call it backspacing around @bucket…

 

[bucket]

Just add or subtract 63.5mm from your current offset.
Moreso, do a little studying on offset and backspacing so that you understand it rather than asking for a magic answer.
And don’t call it backspacing around @bucket…

I'm disappointed... you got that backwards, lol

 

[Grit dog]

I'm disappointed... you got that backwards, lol

Hahaha, crap. That backfired on me! Cheers!

 

[sjones24]

Got it, convert the 2.5 inch spacer into millimeters (63.5), then add in current off set of 18+63.5= 81.5. So this would make it a negative offset of 81.5 which would give me the flush look I desire??

 

[bucket]

Got it, convert the 2.5 inch spacer into millimeters (63.5), then add in current off set of 18+63.5= 81.5. So this would make it a negative offset of 81.5 which would give me the flush look I desire??

Yeah, unless you go wider on wheel width.

 

[Dejure]

On rims and things, about 40 years back, I was running G60's and deep dish chrome rims on my 69 step side. The package looked nice. And I only had to re-do the bearings about every 6 months (daily driver to and from Keyport, Washington, from Bremerton, Washington.

One day, on a trip back home to the Twisp - Winthrop area, I stopped in Brewster for a sandwich. It was there that I'd graduated from high school, back in 69.

While eating lunch, a guy came over and asked if that was my truck outside, then commented on how nice the tires and rims looked. I asked him what he was driving. He said a 56 Chev step side, and that it was running old white spokes and recaps.

I looked at him, smiled and told him, if he could get all his tires on my truck while I ate lunch, my tires and rims were his. He freaked and was out the door like Flash Gordon.

When I got out to my truck again, it was about 4" higher and equipped with marginal recaps. I checked the lug nuts and was off to pappy's house.

Didn't have to repack or replace front wheel bearings for years, after that. So both the guy with the 56 and I were happy.

SIDE NOTE: The guy was Robert Shaw, a really nice guy I used to hang out with from time to time, back in the day when I lived on the east side of the Washington mountains.