# Duramax 1500



## outback loft (Sep 22, 2008)

Well I have finally done it, I have had a Duramax/Allison 6 speed manual sitting in my shop waiting for me and one of my new projects. I took the 6.0 Vortec Max and the Allison 5 speed out of my 1500 and I have now put in a Duramax and 6 speed manual in as well as all the other suspension and drivetrain from the donor truck. I now have a 1500 series truck with 3500 suspension, front end, rear end, as well as the engine that went with it.

Everything went in pretty smoothly as well as the new digital guages for tranny temp, boost, and rear diff temp. I have the Edge Juice with Attitude programmer in as well and a straight exhaust with dual 6" stacks in the bed. The truck is damned fast and not as loud as I thought it would be, with the truck being a regular cab short bed there was no room for me to tuck a muffler in anywhere with the stacks, so until I decide what I am going to do it will stay that way.

When I get a chance to take some final pictures I will do so, I have been swamped with work lately and have been buttoning this truck up now. I will see what kind of mileage I get tomorrow when I do a 500 mile round trip for work.

And yes, this all went into the truck in my signature picture below.


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## rsm7 (Aug 8, 2009)

outback loft said:


> Well I have finally done it, I have had a Duramax/Allison 6 speed manual sitting in my shop waiting for me and one of my new projects. I took the 6.0 Vortec Max and the Allison 5 speed out of my 1500 and I have now put in a Duramax and 6 speed manual in as well as all the other suspension and drivetrain from the donor truck. I now have a 1500 series truck with 3500 suspension, front end, rear end, as well as the engine that went with it.
> 
> Everything went in pretty smoothly as well as the new digital guages for tranny temp, boost, and rear diff temp. I have the Edge Juice with Attitude programmer in as well and a straight exhaust with dual 6" stacks in the bed. The truck is damned fast and not as loud as I thought it would be, with the truck being a regular cab short bed there was no room for me to tuck a muffler in anywhere with the stacks, so until I decide what I am going to do it will stay that way.
> 
> ...


Cant wait to see it! This might call for an audio/video presentation!


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## outback loft (Sep 22, 2008)

rsm7 said:


> Well I have finally done it, I have had a Duramax/Allison 6 speed manual sitting in my shop waiting for me and one of my new projects. I took the 6.0 Vortec Max and the Allison 5 speed out of my 1500 and I have now put in a Duramax and 6 speed manual in as well as all the other suspension and drivetrain from the donor truck. I now have a 1500 series truck with 3500 suspension, front end, rear end, as well as the engine that went with it.
> 
> Everything went in pretty smoothly as well as the new digital guages for tranny temp, boost, and rear diff temp. I have the Edge Juice with Attitude programmer in as well and a straight exhaust with dual 6" stacks in the bed. The truck is damned fast and not as loud as I thought it would be, with the truck being a regular cab short bed there was no room for me to tuck a muffler in anywhere with the stacks, so until I decide what I am going to do it will stay that way.
> 
> ...


Cant wait to see it! This might call for an audio/video presentation!
[/quote]

I will see what I can do for a audio/video presentation.

I am going to have to do a lot more driving to calculate my mileage, in the 507 miles I drive today I only burned a quarter tank of fuel. It was all highway miles with cruise control set at 70 the whole way. I am still using the 27 gallon tank that was in the truck too.


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## huntr70 (Jul 8, 2005)

Might want to make sure that fuel gauge is working.....

If it is, you are getting better mileage than the CRD Volkswagens!!

Even if you used 1/2 tank, that's only 14 gallons, and it calculates to over 36 MPG!


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## outback loft (Sep 22, 2008)

huntr70 said:


> Might want to make sure that fuel gauge is working.....
> 
> If it is, you are getting better mileage than the CRD Volkswagens!!
> 
> Even if you used 1/2 tank, that's only 14 gallons, and it calculates to over 36 MPG!


Well I was thinking the same thing, I topped off the tank today and I did burn more than a quarter tank, I need to figure out what is going on with the gauge. I put in just under 20 gallons, so I burned closer to 3/4 a tank, but that calculates to about 26 mpg.


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## therink (May 13, 2010)

Hi
You will need a different float or sending unit for diesel. The specific gravity of diesel is different than gas, causing inaccurate reading.


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## CamperAndy (Aug 26, 2004)

therink said:


> Hi
> You will need a different float or sending unit for diesel. The specific gravity of diesel is different than gas, causing inaccurate reading.


I could see a very small error possible due to difference between the specific gravity but not a 1/2 tank error. If the sender is not sealed then a bigger effect would be caused by the change in conductivity of the fuel. Not sure if the sender is sealed or not but I would bet it is not.


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## outback loft (Sep 22, 2008)

therink said:


> Hi
> You will need a different float or sending unit for diesel. The specific gravity of diesel is different than gas, causing inaccurate reading.


I could see a very small error possible due to difference between the specific gravity but not a 1/2 tank error. If the sender is not sealed then a bigger effect would be caused by the change in conductivity of the fuel. Not sure if the sender is sealed or not but I would bet it is not.
[/quote]

I had a bad connection for the sending unit, I must have nicked a wire or hooked up something wrong. To isolate where my issue was coming from I ran a new wire direct from the the sending unit to the dash and the made the difference. So now to find where the bad wire is at.


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## CamperAndy (Aug 26, 2004)

Good luck, start at the connections.


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## Joonbee (Jan 18, 2008)

Thats an awesome conversion and I can't see adownside. That has got to be one fast little reg cab. You can probably idle up to highway speed. Better invest in some tires for when that right foot puts a smile in your face. Cant wait to see the pics. And you must really get some strange looks, given the diffent sound and especially going with the stacks. People thinkin "what crazy guy put stacks on a little gasser"?

SURPRISE SURPRISE SURPRISE to quote Gomer Pyle.

Jim


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## Jewellfamily (Sep 25, 2010)

drag strip wheelie bars are extra....


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## outback loft (Sep 22, 2008)

I still haven't gotten a chance to get any pictures up, I have been working like crazy trying to finish up a bunch of projects before Memorial Day. After that I will be slow for a while since nobody wants us around when they are in their summer houses. I have made a few tweaks and I am running my own custom program, when I am easy on the pedal I am getting just about 30 mpg. I am averaging 25 with a mix of easy and aggressive driving. I have already thrown off a few people when they see the stacks and then hear me start it up and then take off!! I have had a lot of weight in the bed so I haven't been too bad about spinning tires, but it happens really easily. I will see what happens for my first time out on the beach with the Outback in the coming month. I think it is going to be interesting with this combo on the beach.


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## willingtonpaul (Apr 16, 2010)

this i gotta see......

sounds awesome !


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