Dually axle options

[Iroc-z]

Hi, new to the square body world. I picked up a 1979 C20 Crew Cab. Want to do a dually swap. I understand the difference between 12 bolt and Dana 70 axles. Has anyone ever swapped in a newer axle? Like a duramax one with disc brakes? Just having trouble tracking down a Dana 70 in my area.

 

[TubeTruck]

I swapped in a 14 bolt out of a 2002 2500hd. Just a matter of cutting the old perches and shock mounts off and welding on new ones.

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[Iroc-z]

If that is all I am up against that’s no problem. If what I am reading is correct square body Dana 70 pickup axles are 72 inches flange to flange. Newer duramax stuff seems to be 74. I feel like an inch a side is not bad and should be able to fit it.

 

[nvrenuf]

The only issue I see with the later axle is wheel size, some of the later model stuff has bigger brakes and require 17” wheels to clear.

 

[Iroc-z]

The only issue I see with the later axle is wheel size, some of the later model stuff has bigger brakes and require 17” wheels to clear.

Are 17 inch wheels the same bolt pattern? Not opposed because I have not bought wheels

 

[nvrenuf]

17’s are available in a multitude of patterns including the typical 8x6.5 that square bodies use. The real trick is the bolt pattern on the axle, the truck brand and year can affect the bolt pattern.

 

[TubeTruck]

Chevy used the 8x6.5 bolt pattern until 2010. In 2011 then went metric and now it's 8x180mm. I forget which years but I want to say NBS-ish they went to a 14mmx1.5mm lug.

 

[Iroc-z]

Chevy used the 8x6.5 bolt pattern until 2010. In 2011 then went metric and now it's 8x180mm. I forget which years but I want to say NBS-ish they went to a 14mmx1.5mm lug.

Good info thank you!

 

[Iroc-z]

Figure I should share a picture of my project. Plan is to do a dually duramax swap. Reason I was asking about the rear axle is I want to find a dually duramax parts truck. That way I have everything I need. If I can utilize the duramax axle it makes life easier.

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[shiftpro]

Figure I should share a picture of my project. Plan is to do a dually duramax swap. Reason I was asking about the rear axle is I want to find a dually duramax parts truck. That way I have everything I need. If I can utilize the duramax axle it makes life easier.

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Are you looking at the wide dually axle with the fenders (my avatar<<) or the narrow version the cab/chassis model had? The narrow axle would allow you to stick duals under your box sides ... but you would need to tub the fenderwells inside the box.
Oh you want Duramax, so I don't what gives with those axle widths.
I just can't see you chopping up your Siverado trim to mount the fenders.

 

[Iroc-z]

Are you looking at the wide dually axle with the fenders (my avatar<<) or the narrow version the cab/chassis model had? The narrow axle would allow you to stick duals under your box sides ... but you would need to tub the fenderwells inside the box.
Oh you want Duramax, so I don't what gives with those axle widths.
I just can't see you chopping up your Siverado trim to mount the fenders.

I want the wide axle. Plan is to put dually fenders on this box. Truck is pretty clean but starting to rust over the wheel wells anyways.

 

[shiftpro]

I want the wide axle. Plan is to put dually fenders on this box. Truck is pretty clean but starting to rust over the wheel wells anyways.

They handle like a big go cart, sticks to the road!

 

[highdesertrange]

so if you plan on making the rear a dually, what are you going to do with the front? are you going to carry two different spares? highdesertranger