18's with 275s on a Duster

I've read soo many threads its mind numbing but, with that said. Stock 73 Duster Disc Brakes up front and A body rear Rear axle currently.
18x9 with a +35 Offset for 275/35/18 fronts
18x9 with a +35 offset For 275/40/18 Rear

I'm thinking ill need a spacer in the front but wasn't sure yet.

Can someone confirm my thinking?

In the front you’ll probably be fine, you might need a small spacer (5mm or less) depending on your steering stop situation.

In the back that’s too much offset for an A-body width 8 3/4, even with BBP axles and brakes. If your springs are in the stock location, you’ll need more like +6 to +13


I dont understand, or care to understand this plus/minus metric offset bulls#!t. What is the backspace, in inches, like the rest of the wheel measurements.
Is the wheel advertised as a 45.8cm x 22.9 cm. wheel?

Blah blah blah, the entire rest of the world is wrong using a 10 based measurement system that makes perfect logical sense and makes pretty much every calculation past basic arithmetic easier. Why we still insist on using a bastardized measurement system that wasn’t ours to begin with I still don’t understand. It’s not “American”, we stole it from the Brits and even they were smart enough to get rid of it.

Offset is easy, it uses the centerline of the wheel which can be a very helpful measurement if you’re changing rim widths but want to keep the wheel centered. It’s just the distance of the wheel mounting face from the centerline of the wheel, measured in mm’s.

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72blunblu, you can disagree if you want, but even in your post quoted above, you talk about offset plus or minus this or that , but then TO BE CLEAR,you explain what the backspace is.
If offset is so self explanatory, why mention the backspace?

Two reasons. One, not all wheels list offset in their advertised specs. Most do, but not all. And two, I know from over ten years of posting here that there are plenty of people that don’t understand offset, regardless of how straightforward it is, so posting the backspace as well just makes it more clear. Know your audience.

Converting back and forth between them isn’t as straightforward, because lots of people forget that backspace is measured from the OUTSIDE lip of the rim, and so their conversions end up being wrong by a 1/2”. So yeah, people screw up backspace too.