Dually Wheel Fitment Help

Android04

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Good day my friends. Well over the weekend my little heart got broken so I'm here hoping someone can help.

At the start of the pandemic I bought a 1985 Single Cab Dually, which was just going to be a quick little project and drive it daily. Well nearly two years later it came completely off the frame, and this past weekend was supposed to be the first drive. This is where I need your help!

I bought some 22" Mega Hole that are direct bolt on. I love them and the front fits great with plenty of room. The front are 22x8.5" and the rear's are 22x6.75". All of the rims are running 265/35/22. When KP cut the wheels he had done a bunch in the past and said they would tuck under the rear fenders and had plenty of previous clients to show the results.

Well with the 6/8 drop they do not tuck under. It's not off by a lot maybe 1/2" or 3/4" and I'm at a loss. It's the only wheels I have so it's a sitting duck for now. The rear tires do balloon a bit since they are a bit big for a 6.75" wheel. So I thought maybe a 255/35 but that's only a .39" in width and .14" in sidewall height difference.

So here looking for help or suggestions. Smaller Tire? Ship wheels back? Narrow Rear End? 3/4 Ton Rear End? Start Drinking? haha

*yeah I know the semi wheels are played out and everyone is doing them, but I love them and building the truck for me. So please no negative comments :)
 

Android04

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Some pictures for reference. The picture of the front is before I put the backs on.

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Salty Crusty

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Most of the guys I know that stepped up to 22.5's use the diff from a cab & chassis, it's the narrowest one. You might look into switching hubs...I sold a diff from a C&C a few years back for $750 to a guy looking to build a lowered dually, the guy drove 300 miles to get it!

I also have an '85 single cab dually, used to belong to my uncle. It's perfect patina and I'm just starting on the build of a pump gas 565 for it. Smallish cam, I'm after torque, tired of the coal burners passing me like I'm tied to a post.
 

Big Chip

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Are the inner and outer wheels interchangeable or does one have a different offset?
 

AuroraGirl

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Are the inner and outer wheels interchangeable or does one have a different offset?
i believe they are the same wheels but there is a spacer between them that they oppose eachother on the rear (so brakes fit behind , i think. I could be wrong here lol) with the dish going in on the back, then the front dishes out .
 

Lu Blunt

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Looks like it has vacuum boost brakes. Was this truck originally a 1 ton dually from the factory ?
 

Grit dog

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i believe they are the same wheels but there is a spacer between them that they oppose eachother on the rear (so brakes fit behind , i think. I could be wrong here lol) with the dish going in on the back, then the front dishes out .

Yes, that is how dually wheels work, save for the spacer, unless one uses one to keep oversize tires from rubbing. But not what he was asking.

To @Big Chip. Doubt the OP bought polished alloy inner duals, but it's possible?
 

Grit dog

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@Android04, srw axles are generally narrower than drw pickup axles, if an axle swap is an option, but would have to measure that they aren't too narrow and cause clearance issues on the inside.

Check this website. Bout halfway down, guy lists the axle widths for different 14 bolt applications. Plus every other thing one would ever want or need to know about 14 bolts.

http://www.billavista.com/tech/Articles/14-Bolt_Bible/index.html


14-Bolt Type* Width WMS-WMS Tube OD / Thickness Applications Hubs* Shafts*
SRW

67.5" 3-3/8" / 0.5" Single rear wheel trucks Type A Type 1
DRW
72" 3.5" / 0.5" Dual rear wheel trucks Type B Type 2
C&C

63.5" 3.5" / 0.5" Cab and chassis trucks Type B Type 1
Van 70" ?? G30 and G35 vans Type A Type 3

Depending how much room you have on the inside to the wheel well or springs, depends how narrow you can go. I'm not certain all the mounting widths are the same between p/u, c&c and van apps, but hopefully this helps.

In the meantime, to get 'er on the road, is there enough thread left on the u bolts that you couldn't slide a shim in and raise the rear a bit? Or is the 8" drop an axle flip?

Truck is absolutely stunning btw! Can only hope mine looks almost that good when I'm done!
 

Android04

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i believe they are the same wheels but there is a spacer between them that they oppose eachother on the rear (so brakes fit behind , i think. I could be wrong here lol) with the dish going in on the back, then the front dishes out .

You are correct, but that is on true Semi Wheels. These are direct bolt on's with a 8 to 10 lug cap to make them look like 10 lug. I think the 10lug looks better then the 8 lug when running these wheels. But I also did not want to run spacers, which is why I went with direct bolt ons.
 

Android04

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Looks like it has vacuum boost brakes. Was this truck originally a 1 ton dually from the factory ?

Yes sir it is a true original C30. Actually all of the metal on the truck is original (other then rockers and one cab corner).
 

Android04

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Yes, that is how dually wheels work, save for the spacer, unless one uses one to keep oversize tires from rubbing. But not what he was asking.

To @Big Chip. Doubt the OP bought polished alloy inner duals, but it's possible?

Unfortunately that is the only way to get these so I do have polished inners as well. Nothing like not seeing your money haha
 

Android04

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Andrew
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1985
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C30
Engine Size
400 SBC
@Android04, srw axles are generally narrower than drw pickup axles, if an axle swap is an option, but would have to measure that they aren't too narrow and cause clearance issues on the inside.

Check this website. Bout halfway down, guy lists the axle widths for different 14 bolt applications. Plus every other thing one would ever want or need to know about 14 bolts.

http://www.billavista.com/tech/Articles/14-Bolt_Bible/index.html


14-Bolt Type* Width WMS-WMS Tube OD / Thickness Applications Hubs* Shafts*
SRW

67.5" 3-3/8" / 0.5" Single rear wheel trucks Type A Type 1
DRW
72" 3.5" / 0.5" Dual rear wheel trucks Type B Type 2
C&C

63.5" 3.5" / 0.5" Cab and chassis trucks Type B Type 1
Van 70" ?? G30 and G35 vans Type A Type 3

Depending how much room you have on the inside to the wheel well or springs, depends how narrow you can go. I'm not certain all the mounting widths are the same between p/u, c&c and van apps, but hopefully this helps.

In the meantime, to get 'er on the road, is there enough thread left on the u bolts that you couldn't slide a shim in and raise the rear a bit? Or is the 8" drop an axle flip?

Truck is absolutely stunning btw! Can only hope mine looks almost that good when I'm done!

You might be my saving grace here. I was strongly considering going with a 3/4 ton rear end, but this seem's better.

I will check it out today, and see what options I have.

As for getting it on the road it is a flip kit drop, so it would have to be one heck of a spacer. I'm actually getting my stock wheels back and just going to slap those on until I can figure everything out.

Thanks for all the kind words and help! I will keep everyone posted on how I get it to work.
 

Big Chip

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Yes, that is how dually wheels work, save for the spacer, unless one uses one to keep oversize tires from rubbing. But not what he was asking.

To @Big Chip. Doubt the OP bought polished alloy inner duals, but it's possible?
I could see the inners were polished is why I asked.
 

Big Chip

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They make a wider dually fender but it sure would be a shame to start messing with that paint! I'd guess a narrower axle is the logical answer.
 

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