98' k3500 dually conversion

[Hog Rush]

Hi, I picked up a nice k3500 single rear wheel long bed truck. It has low miles 104k and had some little issues which I fixed. 

 

I want to turn it into a dually and add a flat bed. 

 

Truck: 7.4 auto 4x4

full floater rear end 4:10 gear

single cab

 

i am just wondering what parts I'll need to make the swap. 

 

I don't want to swap the rear end out, but would rather use parts from another junk truck. Is this possible?

 

i bought a complete rear end, wheels, etc off a 97' 2wd dually. Hoping I can swap out parts instead of entire rear end. 

 

Also will need advice on swapping front wheels to dually wheels

 

thanks

[Logan Lanfear]

I believe the dually used different front hubs or something to get the width out to fit the different wheels.  

The rear just used different wheels, that should work. 

If it were me, I would completely swap the rear end, its not as difficult as it seems.  Why would you not want to go that route?

[Hog Rush]

21 hours ago, Logan Lanfear said:

I believe the dually used different front hubs or something to get the width out to fit the different wheels.  

The rear just used different wheels, that should work. 

If it were me, I would completely swap the rear end, its not as difficult as it seems.  Why would you not want to go that route?

Since the rear end is native to the truck and miles, I'm keeping it under there. 

[Logan Lanfear]

I dont think there's anything you have to really change back there but im not an expert.  Good luck

[SierraDually]

I believe a SRW axle is about 6" less in length than a DRW. I would think swapping axles a better option.  On my Dually there is a different set up for the front brake rotors, wheel stud length is different . And I'm pretty sure leaf spring perches are in different locations to clear the inside tires. If you were to swap the axles you might have to swap springs too. You can't run srw springs and a drw axle and expect it to work. It won't. Well it might but it won't sit right. You might be able to get away with the srw springs if you put like 2" spacer  blocks in on each side. I haven't tried it. 

You can buy a spacer kit for front and rear but I've heard that they put extra stress on the Hubs/bearings so that's a risk you are taking. 

My Dually is not a 4x4. But if you need any measurements from a gmt400 Dually id be glad to go out and look. Mines a stock 7.4/th400 3spd/ 4.10 rear/ 10,000GVW. So maybe a couple measurement from my 4.10 Dually rear would help you see the differences on your srw 4.10 rear. Let me know what measurement u need if any. 

[Logan Lanfear]

14 hours ago, SierraDually said:

I believe a SRW axle is about 6" less in length than a DRW. I would think swapping axles a better option.  On my Dually there is a different set up for the front brake rotors, wheel stud length is different . And I'm pretty sure leaf spring perches are in different locations to clear the inside tires. If you were to swap the axles you might have to swap springs too. You can't run srw springs and a drw axle and expect it to work. It won't. Well it might but it won't sit right. You might be able to get away with the srw springs if you put like 2" spacer  blocks in on each side. I haven't tried it. 

You can buy a spacer kit for front and rear but I've heard that they put extra stress on the Hubs/bearings so that's a risk you are taking. 

My Dually is not a 4x4. But if you need any measurements from a gmt400 Dually id be glad to go out and look. Mines a stock 7.4/th400 3spd/ 4.10 rear/ 10,000GVW. So maybe a couple measurement from my 4.10 Dually rear would help you see the differences on your srw 4.10 rear. Let me know what measurement u need if any. 

I definitely agree with the swapping axles.  I didn't know if they were a different lengths or not.  

[SierraDually]

I believe the drw axle is 6" longer than the srw axle except on cab and chassis models or motor homes. They have their own suspension and frame differences that you don't have with a pickup. 

So, you can get a Dually axle from the same year in two different lengths. That's something to watch for. Avoid the cab And chassis axle. I've seen problems trying to convert with those. you want the longer one in my opinion. 

[SierraDually]

Another thing to keep in mind is the clearance lights. Might depend were you live, but DOT regulations require the amber lights on top of the cab and the extra red lights on the tailgate or below the tailgate. It is to warn other motorists at night that the vehicle is wider than a standard vehicle. That's in addition to the Amber and red markers on the Dually fenders. 

[slfwilrr]

I'm looking at converting a dually 2 wd to 4 wd. Anyone have any experience with this?

 

[Logan Lanfear]

8 hours ago, slfwilrr said:

I'm looking at converting a dually 2 wd to 4 wd. Anyone have any experience with this?

 

something to start a new thread for

 

[ElectricBill]

On 12/6/2017 at 12:11 PM, Logan Lanfear said:

I believe the dually used different front hubs or something to get the width out to fit the different wheels.  

The rear just used different wheels, that should work. 

If it were me, I would completely swap the rear end, its not as difficult as it seems.  Why would you not want to go that route?

Yes the front hubs are different on a dually truck. The Budd type reversible rims won't allow tire clearance for the sway bar or tie rod. You could just leave the front alone I suppose.