Lmm in lbz

Nov 27, 2022
53
4
8
Hey I’m an 18 year old who snapped a crank in my lbz motor with 250k miles on it. I got quoted out a decent amount of money to get everything fixed but I found a cheap lmm duramax with 109k on it to drop in. Just wondering if anyone has any tips and tricks to doing the swap I saw a few people have done this so figured I’d ask around. Just curious on the differences that I’d have to look out for to complete the swap. Any help is appreciated this is my first motor swap but I’m mechanically inclined. Thanks
 

gmduramax

Shits broke
Jun 12, 2008
4,077
250
83
Nor cal
Just use your LBZ engine harness on the LMM motor. I believe the LMM has a coolant port on the oil cooler that the LBZ doesn’t have, so you’ll have to use your coolant crossover from your LBZ and either the oil cooler or block the port on the LMM cooler. I don’t think anything else is physically different, could be missing something tho
 
Nov 27, 2022
53
4
8
Just use your LBZ engine harness on the LMM motor. I believe the LMM has a coolant port on the oil cooler that the LBZ doesn’t have, so you’ll have to use your coolant crossover from your LBZ and either the oil cooler or block the port on the LMM cooler. I don’t think anything else is physically different, could be missing something tho
Okay and do you know if I’ll have a communication issue with my tcm or ecm or anything? Or even my gauge clusters and stuff for that matter
 

1FastBrick

Well-known member
Dec 1, 2016
2,551
1,083
113
Junkyard
Okay and do you know if I’ll have a communication issue with my tcm or ecm or anything? Or even my gauge clusters and stuff for that matter
Like he said, Use the LBZ wiring harness on the LMM motor. The basic long block is the same. It should not have an communication issues since you are reusing your Harness with the ECU and TCU
 
Nov 27, 2022
53
4
8
Not a problem at all
Okay perfect. And I’m not sure if anyone is familiar with tuning but I am going to be running the lmm with no dpf or egr do I still have to get it tuned for a dpf delete to prevent regen/limp mode? Or will it not carry over due to me using the ecm from the lbz. And the ecm from the lbz is tuned with the PPE hot +2 ET race tuner which I was reading will delete the regen also.
 

shakenfake

Moron
Sep 15, 2022
322
125
43
Shlumpt, TX
Are you retarded?
He asked if he is going to have to tune out the LBZ ECM for DPF. Obviously not since it didn't have DPF.

BTW I have 27 posts across maybe 5 threads with 20 of those posts in my own thread. 4 Posts being in off-topic esque threads, one of them being in your vendor thread (which was in fact my fault so I apologize) 2 of them asking a question in an interior thread and one of them being in this here thread (this post being my 28th so two)
Please point me to where I have said some incorrect things lately across my 28 posts and I will gladly apologize. As of now though you are the one incorrectly posting. :)

Looks like we both could learn to read the posts better.
 

1FastBrick

Well-known member
Dec 1, 2016
2,551
1,083
113
Junkyard
Are you retarded?
He asked if he is going to have to tune out the LBZ ECM for DPF. Obviously not since it didn't have DPF.

BTW I have 27 posts across maybe 5 threads with 20 of those posts in my own thread. 4 Posts being in off-topic esque threads, one of them being in your vendor thread (which was in fact my fault so I apologize) 2 of them asking a question in an interior thread and one of them being in this here thread (this post being my 28th so two)
Please point me to where I have said some incorrect things lately across my 28 posts and I will gladly apologize. As of now though you are the one incorrectly posting. :)

Looks like we both could learn to read the posts better.
Why Don't you take it down a notch turbo? There is no need for name calling. Boy, You need a role model...

Source: https://www.youtube.com/watch?v=pqVKZwWkMRs&ab_channel=A-3OVO
 

Bdsankey

Vendor
Vendor/Sponsor
Feb 1, 2018
4,179
1,289
113
Larsen, Wisconsin
Are you retarded?
He asked if he is going to have to tune out the LBZ ECM for DPF. Obviously not since it didn't have DPF.

BTW I have 27 posts across maybe 5 threads with 20 of those posts in my own thread. 4 Posts being in off-topic esque threads, one of them being in your vendor thread (which was in fact my fault so I apologize) 2 of them asking a question in an interior thread and one of them being in this here thread (this post being my 28th so two)
Please point me to where I have said some incorrect things lately across my 28 posts and I will gladly apologize. As of now though you are the one incorrectly posting. :)

Looks like we both could learn to read the posts better.
Simmer down tiger. Reacting like that’s a real fast way to be shown the door.

I took your post as saying he didn’t need to swap the DPF since the LBZ didn’t have one to which I was replying that didn’t matter in the slightest as he’s swapping engines not complete exhaust etc. My apologies, been a long few weeks with my surgery and all.

If you want to go was up your panties, I suggest the Cummins forums. Those girls love to fight.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,690
5,847
113
Phoenix Az
Okay perfect. And I’m not sure if anyone is familiar with tuning but I am going to be running the lmm with no dpf or egr do I still have to get it tuned for a dpf delete to prevent regen/limp mode? Or will it not carry over due to me using the ecm from the lbz. And the ecm from the lbz is tuned with the PPE hot +2 ET race tuner which I was reading will delete the regen also.

You are over-concerning yourself with the electronics and everything else the LMM has compared to the LBZ.

Let’s start with “how much do you know and understand about the truck you are working on?”

What you are going to do is swap in an engine that is a “long block”. This means strictly an engine that is complete from heads down. It can include injectors and front accessories. If you are unsure of a part working from the lmm into the lbz, just change it for your lbz part. As GMDuramax said, it’s all basically the same other than one has more emissions on it, the oil cooler and some other small details.

You WILL be re-using your engine harness, ecm, tcm, lbz exhaust, any egr delete stuff you may already have on the lbz, lbz intake, and anything else attached to the top of the lbz engine currently.

You have the OPTION to use the lmm turbo, exhaust manifolds, up pipes, fan and fan clutch, water pump, fan pulley, and power steering pump. I’m unsure if the lmm alternator and a/c compressor are the same though.


Who’s going to be doing the work?