LB7 swap... anyone done this?

[drewmech]

After googling and doing the search here on the forums I haven’t found anything on people dropping in a LB7 Duramax. On other forums I’ve found people who have bolted the LB7 to a TH400. Just curious if anyone has any other info on this. Thanks!

Also Yes I know modifying the truck will hurt it’s value. As I don’t intend to sell the truck ever I’m not as concerned about it. I was fixing some issues on the truck and had to drop the oil pan and found a few small cracks on the main webbing of the block so the motor that’s in there isn’t long for this world. I missed the boat on the P400 engines as they are out of production and replacing the NA 6.2L with another one or even a turbo 6.2/6.5 seems like asking for more of the same issues. I have found a couple of used P400’s on eBay however I’ve found used LB7s cheaper and in its stock configuration the LB7 packs more punch. So While I’ve got to pull the motor anyway figured it’s time to start figuring out which direction to go. Thanks again!

 

[Jeepadict]

Fair caution, the LB7 comes with it's own issues...imperfect machine built by imperfect humans...just like the 6.2/6.5L. I have a LB7 in my Silverado, and they're great motors...shy the injectors headache. Support and mods abound since soo many were made. Having a quality tuner is critical in any Dmax project. I'd reccomend ditching the 400 in favor of the A1000, a far superior unit in my opinion...adapting the A1000 to your choice of t-case is simple.

There's quite a few squarebody Dmax swap groups on Facebook that are plentiful of info. It's a topic of some severely differing opinions ranging from strength of the frame to which kit to use.

Using the Tapatalk app there's also a few Dmax forums that have plenty of threads dedicated to swap info.

Sent from my SM-G970U using Tapatalk

 

[drewmech]

Thanks for the info. I deleted my Facebook years ago just not much for that whole thing. I’ll keep googling I guess. Thanks for the suggestion on the transmission.

 

[chevymike]

One thing I read about the Duramax swaps is they are a very wide engine. This can cause problems getting them to fit in some applications.

 

[Bulldogger]

People are pushing Dmax's into HMMWVs with their tight engine bays, so I assume a CUCV will be a relative cakewalk. Not that it won't have plenty of oopsies to deal with, but I'm sure it can be done with a big enough hammer.
Don't forget pictures!
BDGR

 

[shotty]

Not too up to speed on duramax stuff but I did notice that you can get conversion mounts here https://www.thedieselpage.com/conversionmounts.htm

I'm going to stick with a 6.5 in mine, seems much easier

 

[chevymike]

People are pushing Dmax's into HMMWVs with their tight engine bays, so I assume a CUCV will be a relative cakewalk. Not that it won't have plenty of oopsies to deal with, but I'm sure it can be done with a big enough hammer.
Don't forget pictures!
BDGR

Agree, big enough hammer anything will fit. LOL

I am going an easier way with mine. Gen VI 454 big block. Since it was a factory option, it should fit without any issues.

 

[Jeepadict]

Agree, big enough hammer anything will fit. LOL

I am going an easier way with mine. Gen VI 454 big block. Since it was a factory option, it should fit without any issues.

I have my eyes set on an LQ4/4L80E/241 swap into mine. The LS platform outperforms the SBC/BBC platforms with ease.

Sent from my SM-G970U using Tapatalk

 

[linemech31]

I dont know if you already have a lb7 or a line on getting a good deal on one.... but if you can get an lly or preferably lbz you will have a much happier wallet down the road. I had an lb7 and the injector issues are big money to fix. I moved on to a lly engine and ran it 68k miles without issues. Now i have an lbz (2006) with 193k miles. 170k of which have been with a tune of 90hp. All i have done to it are glow plugs and a water pump. The allison transmission has been good as well. The red line is 3200 rpm... the th400 is going to run out of gears real quick. But i bet it would impressive 0-60.

 

[Senderofan]

Also be aware that GM increased headbolt torque specs in early 2002. I had a late 2001 built LB7 and had a head gasket fail at @ 55K miles....injectors at 75K. The GM Master Duramax Certified Mechanic broke the bad news on the torque spec change, If you want to make significant power increases.....swap in an ARP headstud kit and don't look back.

The Allison 1000 is a great tranny.....but be prepared to spend $XXXX's to upgrade the internals and torque converter if you are going to spice things up. About 50 extra horses and 100 ft/lbs of increased torque is about max....for the Allison that was married to the LB7 at the assembly line. They'll slip in the higher gears ( go in to Limp Mode ) Causing frictions and steels to burn. You will also develop cracks around where the bolts go in to the torque converter. I spent @ $5K to have my Allison upgraded to a SunCoast Stage 4 with a billet covered triple disk torque converter.........That bad boy handled every upgrade thrown its way with ease.

Best of luck........Modern diesel's respond well to simple things like a big tune or you can step it up with a bigger turbo, compounds, propane injection or nitrous......all fairly easy things to do singularly or in combination.. I ran a Quadzilla Race tune, modified turbo and a PS2000 propane injection system. I had an AirDog lift pump installed after new injectors...helped feed the motor and remove the bubbles from the fuel.

 

[Garagefull]

I am contemplating a D Max swap right now. I really like 6.2/6.5 engines, but with the lift kit and 37 inch tires and all the gear they just don’t have an ample supply of grunt. I was told the early Duramax vans came equipped with a 4L 80 using a standalone controller. I thought about investigating that. I’ve been on the fence about this conversion, as it is a unmolested truck at this point other than the lift and tires

 

[LT67]

My DD is an 04 GMC D'max truck. I just don't want that much power in one of my cucv trucks lol

 

[Garagefull]

Well,im out. I figure by the time it’s installed I’m looking at nearly a $5-7k conversion by the time I get drive shafts cut etc. i’ve got an F code 6.5 turbo, thought about ditching the DS4 and converting it over to a DB2. I’ve got to get just a little more grunt into the old girl, and I’m not really a gasoline engine fan.