Duramax in half ton chassis

[MAXX IT OUT]

I am working on pulling a new plan together for the engine and trans out of my 01 and eventually put it in one of my C10s. Have been throwing around the idea of putting my semi built engine and trans in a 2008+ Suburban/Tahoe chassis for stronger frame than the stock 70's frame, plus keep 4 wheel drive. I could use the frame from my 01, but I don't want the extra weight and frame height that comes with the 2500 frames. I believe that the duramax should bolt in with factory motor mounts, but not sure what the axles can take in these chassis. I have hear of guys going to smaller/lighter rear ends in drag trucks for the weight savings over the aam 11.5 rear ends, but I am not sure what that rear axle is out of. I am hoping to end up with a sub 5000LBS street truck thats a bit more fun than drive.

 

[2004LB7]

The Ford 9 inch axle is often used for weight and appears to be quite strong with the right parts

Not sure about the front axle

 

[Chevy1925]

The 9” wont like shock loading under high torque/hp situations. You basically need a big ass 40 spline full floater with the 10” ring gear at that point. If your not acting like a kid on the street, a semi float 35 spline axle should last you a good while. Ring and pinion would be the weak point

Cost becomes a big factor as well.

 

[MAXX IT OUT]

I have been trying to find some of the posts about it on here, either it was a Chevy half ton rear axle or the 12 bolt full floater from a 6.0 LS 2500 truck.

 

[Chevy1925]

Check Toms 1500 build out. I think he did the 9.5 semi float rear axle

 

[MAXX IT OUT]

After some digging i found Tom Thread, https://www.duramaxdiesels.com/forum/threads/duramax-in-a-half-shell.27056/page-4, I believe he ended going with a 10.5 FF, I would like to stay with a 6 bolt axles axle to make the wheels the same front and back. Need to do some more research, but the Denali might have came with the 9.5 SF.

 

[TheBac]

Do not, under any circumstances, use a 2wd frame with rack. You'll be hacking up your oil pan to get the engine to drop down far enough. Found that out.
4x4 frame should work without mods, as Chris did years ago (look up threads by @thunder550). Worst that can happen is you'll have to space the front diff down using a lift kit mount.

9.5 would be plenty strong on the street, especially if you put a detroit or torsen in it.
Now that ive had 10 years to think about it, I'd do a 10.5 for racing. You'd be using the disc brakes to hold the c-clip 9.5 axles in, which is a nono at tech.

You will need adapters to use 1500 motor mounts. There are LS mounts similar to merchant mounts available, too. Keep in mind, Dmax pass side mount is offset bc of the starter. Nothing that can't be overcome.
I believe there's an adapter Trans mount made nowadays for the 1500s that can be used with the Allison (same as 4l80).

I'm thinking I may restart mine now that I'll have ample time on my hands.

 

[MAXX IT OUT]

I remember thunder550 build and thought about using a truck chassis, but in Iowa they are all rusted and broken behind the cab. Seems to be plenty of newer Yukons, Tahoe and Suburbans around with blown engines and or transmission for a decent price. I am not sure if the newer 2008+ 4 wheel drive ones with a R&P will have the issue with oil pan clearance. I have seen Duraburb conversions in that body style so figured it should be possible.

 

[NC-smokinlmm]

I’ve got my 2010 1500 making more torque than you probably will and the stock axles are holding up after a Detroit truetrac swap in the rear. Burnouts daily on 22’s with 33” mud tires.

 

[Chevy1925]

I’ve got my 2010 1500 making more torque than you probably will and the stock axles are holding up after a Detroit truetrac swap in the rear. Burnouts daily on 22’s with 33” mud tires.

The difference is traction. If he keeps the ladder bar setup from the 1500 tahoe and runs a sticky street tire, be surprised what it will snap.

Thats why i didnt say “na dont run it”, its more “if you are going to swap axles, might as well make it worth it”.

 

[TheBac]

Also, you've got to consider the cooling stack and Allison-to-body fit.
IIRC, the Ally will fit under the 1500, but its really really close to the floor, within an inch. Would need to bend floor lips inward.
If you decide to use the Dmax radiator and such, you'll have to use a progressive 2" lift in the front of the truck toward the rear to fit it all. That also solves the Ally fit.
You could use the 1500 radiator setup, but would obviously need a much thicker radiator. Hi volume electric fans would have to be used, too.

 

[MAXX IT OUT]

I’ve got my 2010 1500 making more torque than you probably will and the stock axles are holding up after a Detroit truetrac swap in the rear. Burnouts daily on 22’s with 33” mud tires.

What rear does your truck have? Mark tuned most of the low end toque out of it, but if I remember from when he dynoed it, its still 1000+lbs so as James said, if it hooks up on good street tire it could get expensive.

Also, you've got to consider the cooling stack and Allison-to-body fit.
IIRC, the Ally will fit under the 1500, but its really really close to the floor, within an inch. Would need to bend floor lips inward.
If you decide to use the Dmax radiator and such, you'll have to use a progressive 2" lift in the front of the truck toward the rear to fit it all. That also solves the Ally fit.
You could use the 1500 radiator setup, but would obviously need a much thicker radiator. Hi volume electric fans would have to be used, too.

Not sure on the cooling stack set up I will be running, but my cummins swapped C30 I just used stock style 4 core aluminum radiator and it does fine to the point where I don't run the electric fans to get it to get to 180 degrees.

 

[MarkBroviak]

For what it's worth, I have a 2007 GMC Yukon Denali XL with an LMM engine and transmission in it with all the 1/2ton running gear including the transfer case and absolutely love it. It has a single low torque higher rpm hp 400hp tune in it and it drives amazing. Like previously said, if you don't beat it like a 16year old kid it does quite well with zero issues. Currently has 320,xxx miles on it. When it fails I will probably put the 10.5" rear diff in it. I have tuned and driven a ton of different swaps and as far as the suv's goes the 1/2ton rides and drives so much better than the 3/4ton's do but obviously they won't take the abuse as well.

 

[NC-smokinlmm]

What rear does your truck have? Mark tuned most of the low end toque out of it, but if I remember from when he dynoed it, its still 1000+lbs so as James said, if it hooks up on good street tire it could get expensive.

Not sure on the cooling stack set up I will be running, but my cummins swapped C30 I just used stock style 4 core aluminum radiator and it does fine to the point where I don't run the electric fans to get it to get to 180 degrees.

It’s got an 8.6 in it. I can’t be more mean to that rear end. I’ve beat on it severely. Several hundred 1/4 mile passes at over 700 tire hp and torque and it’s still going strong. Same with the transfer case front end and all the factory driveshafts and u joints. Only thing I changed was building the transmission and the Detroit in the rear end with a girdle. I daily drive this truck for my mobil repair business so it gets used and abused. The gm drivetrain in these trucks still amazes me.

The 408 in my truck stays nice and cool with the factory stack in place. I’d leave the cooling alone and see if it can handle the diesel. I think it can, my 408 barely gets over 200 degrees when I’m pounding on it hard,. It is my understanding that cooling is based on horsepower, I’m right at 1000 hp and torque with the 408 and it’s happy, I can’t see a diesel having that much more cooling demands than a big LS.

 

[MAXX IT OUT]

For what it's worth, I have a 2007 GMC Yukon Denali XL with an LMM engine and transmission in it with all the 1/2ton running gear including the transfer case and absolutely love it. It has a single low torque higher rpm hp 400hp tune in it and it drives amazing. Like previously said, if you don't beat it like a 16year old kid it does quite well with zero issues. Currently has 320,xxx miles on it. When it fails I will probably put the 10.5" rear diff in it.

Is that the AWD transfercase? That 10.5 would be a custom rear end or a stock swap in?

It’s got an 8.6 in it. I can’t be more mean to that rear end. I’ve beat on it severely. Several hundred 1/4 mile passes at over 700 tire hp and torque and it’s still going strong. Same with the transfer case front end and all the factory driveshafts and u joints. Only thing I changed was building the transmission and the Detroit in the rear end with a girdle. I daily drive this truck for my mobil repair business so it gets used and abused. The gm drivetrain in these trucks still amazes me.

The 408 in my truck stays nice and cool with the factory stack in place. I’d leave the cooling alone and see if it can handle the diesel. I think it can, my 408 barely gets over 200 degrees when I’m pounding on it hard,. It is my understanding that cooling is based on horsepower, I’m right at 1000 hp and torque with the 408 and it’s happy, I can’t see a diesel having that much more cooling demands than a big LS.

I will give the factory stuff a try.

 

[NC-smokinlmm]

I probably need to upgrade my oil cooler. Only thing that I watch closely.

 

[MarkBroviak]

Is that the AWD transfercase? That 10.5 would be a custom rear end or a stock swap in?

I will give the factory stuff a try.

It has the 2wd, auto4hi, 4hi, 4lo 1/2ton case. The 10.5 would be custom because of the coil spring 4link rear setup in them.

 

[Chevy1925]

Little plasma cutting, some tabs and plate, easy peasy

 

[1FastBrick]

We had a guy on PT .net that build a custom 5 link 9.5 housing for a guy when he couldn't find one for his avalanche. user name was AxisT6. He also made a 6 lug 10.5 for some one. So it can be done....

TECH: 6 Lug 14 Bolt SF into an Avalanche - PerformanceTrucks.net Forums

GM Drivetrain & Suspension - TECH: 6 Lug 14 Bolt SF into an Avalanche - This purpose of this project is to prep. a 6 Lug 14 Bolt SF axle into a 1/2 Ton Avalanche. Here is what will be done: 1. Geared to 3.73 with a Detroit True Trac 2. New Bearings and Seals 3. Adapt Factory Disk Brakes 4...

www.performancetrucks.net

10.5 Full Floating 14 Bolt....with 6 lugs - PerformanceTrucks.net Forums

GM Drivetrain & Suspension - 10.5 Full Floating 14 Bolt....with 6 lugs - Felt I should put this here. Some of you are making some very serious power. Sure the 9.5 14SF is an upgrade, but it is still a C-clip style axle that could be an issue if you snap a shaft. A full floating axle is one where...

www.performancetrucks.net

You can get a custom C clip eliminator for the 9.5 but it's not cheap... The 10.5 would be far easier to get started with.

 

[MarkBroviak]

My biggest concern with the axle swap was getting the wheel speed sensors because the stock setup has tone rings on the axles themselves for the abs.