Appropriate Wheel Offset for 18" Wheels?

[72bluNblu]

Dr. Diff 13 inch cobra front, 8-3/4 big brake kit rear. Stock width A body 8-3/4 currently or B body 70-74 if I can get one in Alaska. Spring relocation in the rear, and will mod the outer wheel well a bit for some clearance if needed.
Tubular uppers, USCT full stiffening kit.

In the front you'll want to check the rim to UCA clearance at full steering lock and suspension extension, and then the tire clearance at full lock on the frame. You may need a small spacer, it will depend on what UCA's you've got and how tall your front tires are going to be. And how tall the steering stops are on your lower ball joints, they vary quite a bit.

In the back if you have a full 3" relocation and mini-tub with the A-body 8 3/4 housing, BBP brakes and disks you should actually be fine depending on the tire size you want to run. 72BBswinger was running 18x12's with 9.1" of backspace and 335/30/18's on his Dart with a '67 B-body rear and rolled quarter lips. If you do the math on the 67 B rear vs an A-body that would work out to needing ~8.25" of backspace with an A-body rear. With 11" rims you wouldn't get that wide of a tire so you'd probably be fine

 

[onelapduster]

Good to know for the clearances on the front end. The GTS still needs a ton of metal work. But I have everything to make it a roller once I am ready.

Looking at 285/30 on the front and 315/30 on the rear.

On the rear, keeping the A Body 8-3/4, means I'll likely use 2.25 or 2.5 inch spacers to get the wheels out where I want them. The B body rear solves the issue, and even an 8.8 could make it interesting width wise.

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Side note, been following your build from the beginning (despite my joined date), really inspired my 75 Duster build over the years as I've copied many of the things you've done. Cool to know you're still on here and contributing to the boards.

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I should probably post my two A Bodies, the duster is a dastardly build that'll catch flack, but I'm making it up to the mopar gods with my GTS build.

 

[72bluNblu]

Good to know for the clearances on the front end. The GTS still needs a ton of metal work. But I have everything to make it a roller once I am ready.

Looking at 285/30 on the front and 315/30 on the rear.

On the rear, keeping the A Body 8-3/4, means I'll likely use 2.25 or 2.5 inch spacers to get the wheels out where I want them. The B body rear solves the issue, and even an 8.8 could make it interesting width wise.

.

Side note, been following your build from the beginning (despite my joined date), really inspired my 75 Duster build over the years as I've copied many of the things you've done. Cool to know you're still on here and contributing to the boards.

.

I should probably post my two A Bodies, the duster is a dastardly build that'll catch flack, but I'm making it up to the mopar gods with my GTS build.

Thank you!

For a 285 up front you'll definitely have to do some fender work, especially if you're going to be running lower (which I assume you are)

In the back, where are you trying to put the tires? Well outside the quarters? Comparing to 72BBswingers set up, which he had to do quarter work to clear, your set up with an A-body 8 3/4 would only leave about 5/8" more space to the quarter. Moving it 2.5" would put it well outside the quarter panel.

You should totally start a build thread for your cars, I'd love to see what you've done!

 

[oi81b4uu812b4]

I use both 285/30/18 on a 10+" wide rim and 275/ 35/18 on a 9-1/2" wide rim on the front of a Duster. The 10" required me to add about an 1-1/2" to he lower fender support rod and I swapped out the upper control arms with SPC Adjustable Control Arms. I didn't have to do any other metal work, but it's a Duster and I am not a good reference for other cars front fender well arch shape. Some lower tie rod ends have trouble clearing he inside of a 10" wide rim. I see some people just replace them use Heim rod joints ( always looks sketchy to me ). What will clear your tie rod end, depends more on he shape of the inside of the rim and what tie rod you've got, where you want weights placed...

My 1970 Barracuda has 315/40/18 on the front and 355/30/19 on the back and swap them from time to time with 335/30/18. I really just measure to see what fits and make the widest tire fit.