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Posted By: Superlongpowerstroke03 Bolt in dually rear axle? - March 28th 2018 11:17 pm
Hi all!
I’m new to the forum but not to vanning, my latest project is a 2003 Ford E350 extended wheelbase 15 passenger Econoline with a 7.3L powerstroke diesel V8.

I bought this vehicle primarily to pull our 35 foot travel trailer, I wanted something very reliable and a good platform to modify. My plans are dual wheel rear axle, The normal 7.3 L engine mods, front inner cooler, 2008 through 14 front end, and an amazing set of super long chrome side pipes! 22 1/2 inch semi wheels are slated at a later date!
I’m pretty well on the way to having everything rounded up I need except I am stumped on what rear axle to use.
Being I am doing the work myself and am of course like most others on a pretty strict budget I am hoping to find something that is bolt in and the same bolt pattern as the E-series van which is 8 x 6.5. I’m also hoping to find something with a 4.10 gear and the same bolt pattern with disc brakes.
I think that some dodge trucks have the same bolt pattern possibly Chevrolet also, I would just like to find something that has as little modifying as possible.
I know that a box van and or ambulance rear differential will bolt in place but is not wide enough for the standard van chassis.
I have found a ton of different places to source numerous different rear ends but none of these places have given me any good ideas on how to go about figuring out what I want to do.
Any help on this matter would be greatly appreciated!
Thanks
Posted By: frscke1 Re: Bolt in dually rear axle? - March 29th 2018 1:48 am
Welcome to the site SLPS ....

Does the rear end of this work ? May not be a direct swap, can be fab'ed to work.

https://sandiego.craigslist.org/nsd/pts/d/1989-forddually/6539699593.html
Posted By: Superlongpowerstroke03 Re: Bolt in dually rear axle? - March 29th 2018 4:28 am
I don’t know, that’s why I am asking... I’m really trying to stay in the later model years so that I retain the rear disc brakes. But thanks for the response, thought and effort!
Posted By: CatFish Re: Bolt in dually rear axle? - March 29th 2018 1:27 pm
The Ford ambulance swap should be a bolt-in or, at the least, require minimum fab work. Not all will fit of course. If you can find a bone yard that buys a lot of Ford ambulances you might get lucky enough to measure, pick and choose. The ones that will work are the ones made similar to the dually pick-ups. The inside rear tires will track closely to the front tires and the outside rears just stick out there.
If you go with some other manufacturers set-up your fab time and hassle will be aligning the driveshaft as different manufactures offset the engine/trans differently.
As an aside, there are vendors that sell dually conversion kits (including fenders) for E350 vans that use the existing 8-lug differential.

Edit: The 7.3 vans came with a smaller turbo than the pick-ups (and a slightly lower HP/torque rating). If you can make it fit, the larger turbo will help bring the power up to the pick-up level. Finding room under the doghouse will be a challenge, Ford couldn't do it. shocked
Posted By: Superlongpowerstroke03 Re: Bolt in dually rear axle? - March 29th 2018 1:36 pm
Thanks for the response, I really am trying to not use the conversion that uses adaptors. I want a full rear end swap out.
I am really hoping to find someone else that has done the trial and error and can point me in the right direction.
You have made some very good points and I really appreciate it.
I need to find some ambulances... that would be the bees knees as far as bolt in but I keep hearing they and box trucks have a more narrow rear frame section and in turn has a more narrow rear axle and standard wheel/tire will run into inner fender well.
I’ll do some checking as soon as I find some ambulances.
Thanks
Posted By: CatFish Re: Bolt in dually rear axle? - March 29th 2018 1:41 pm
Look for motorhomes! Class C's can be an excellent choice and most are the wide body type.
Posted By: frscke1 Re: Bolt in dually rear axle? - March 29th 2018 2:32 pm
Catfish I totally agree why didnt I think of that.... yes a class "C" motorhome rear will be a direct fit.
Posted By: Uncle_Fester Re: Bolt in dually rear axle? - April 01st 2018 9:33 am
I wish I knew what rear end was used in building Wolf-Den. I did not notice any signs of modification beyond moving the spring perches some, about 2” or so IF I recall right, but not 100% on that.

I do know that up to _______ all duality rears had 8x6.5 bolt pattern. After that year, Ford changed to a different bolt pattern.

Best of luck and keep us posted !
Posted By: CatFish Re: Bolt in dually rear axle? - April 01st 2018 8:51 pm
Like this.....Ken's Superbeast
https://www.vanning.com/threads/ubbthreads.php/galleries/231792/1
Posted By: Superlongpowerstroke03 Re: Bolt in dually rear axle? - April 03rd 2018 1:14 pm
Yes! Like that but that van is a somewhat factory built dually from Quigley. I have tried to contact them but they will not divulge any information except that they use their own Axles. I’ll check on the class C’s but I think they are the same as a box truck which is too narrow.
(Possibly same axle as the trucks)
I’d really like to find a E450-550 and use the 10 bolt 19.5” wheel/tire combo until I can afford to step up to Semi 22.5” wheels. (That happens when it gets 4x4’d!)
Again, thanks for all the comments!
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