Diamondback Diesel

05/29/2026

L5L number 2 is on its way! We’ll be putting together the 2nd L5L to put in this beautiful 2015 Denali!

If you haven’t seen what the L5L is all about yet feel free to check out our announcement post linked below!

https://www.facebook.com/share/p/18VfduMKQt/?mibextid=wwXIfr

We are also looking at gauging interest for these kits and would like to offer 4 additional drop in L5L motors! They will have everything minus harness, fuel or turbo but can also add all of that for anyone looking! Preorder now as they’ll go fast!

If you’re interested in purchasing an L5L engine shoot us a message or give us a call!

The 4 available will be first come first serve and will be built in the order they are purchased. We’re expecting all of them to be done end of June to early July.

These will be overhauled engines so they are not what we would call a full rebuild unless requested. We are trying to keep these intro production units a little cheaper in the beginning here to have some more of these motors out in the wild.

If you’re serious about purchasing one feel free to reach out and we can discuss in detail what they all entail.

We still do not have 100% finish pricing on these yet but for the drop in “overhauled” motors it will be around the $14,000 mark

As for the kits once they’re available where you provide your own short block we’ll be offering 3 versions of the kits

Kit 1-only the modified/required parts will be provided absolutely zero covers, block etc you source out the majority of the L5P parts yourself

Kit 2-a complete kit but all reusable parts including, valve covers, intake runners, heads, fuel rails, fuel lines etc will be cleaned/used parts

Kit 3-will include all the same parts as kit 2 except all parts will be new or fully reconditioned (most will be new).

Just to get some numbers in people’s heads we’ll list BALLPARK pricing of the kits once they’re available.

Kit 1-$6500

Kit 2-$9000

Kit 3-$11500

One more time. These prices are BALLPARK FIGURES. We are still waiting on some pricing for some of the custom parts to fully finalize pricing. As of now all custom parts are made as needed.

Please share and let us know what your thoughts are and any other feedback!

05/12/2026

Following up with yesterday’s posts about the L5L here is a more in depth description of what’s all going on with this setup and our plan to get these kits out to you! This is a pretty long post but worth the read!

Hey, my name is Brandon and I’m the owner of Diamondback Diesel. We are a Duramax only shop in Plymouth WI, and we have a pretty exciting project here that I wanted to announce to all the LML owners that are sick of broken cranks and cracked pistons left and right! We have put together the worlds first L5L Duramax! We have successfully engineered an L5P long block to run off of LML electronics and injectors!
This is NOT an L5P swap which requires many more parts and harness changes.
I’m going to list the basics of what it actually is and our plan to potentially provide kits for guys are that are looking to install a better motor without having to spend BUILT motor money.

We have the L5L in our 2015 dually tow rig with 100 overs, compound s480/64vgt with a 10mm cp3 and went a step further and fully rebuilt the motor with stock L5P crank, stock rods and Mahle powerpak L5P pistons! We tested it on the Dyno at the Richland center hub city dirt drags in southwest WI and we have it on a very conservative 718HP to the wheels! Next time we’ll push it even further! This truck towed our L5P race truck 3 hours there and 3 hours back like an absolute dream!

The basics go as follows
L5P custom heads
L5P block/rotating assembly
L5P valve covers and fuel rails
L5P intake runners and Y bridge
L5P thermostat housing
L5P exhaust manifolds
Custom Up pipes
LML injectors
LML factory style turbo
LML engine covers
LML all wiring harness’
Adapter harness’
DBD L5L CP3 kit

Again these are just the basic components for the swap and there will be many updates and small changes to make this the best quality and simplest installation possible!With this swap there are two major gains with this setup over a stock or even built LML. One gain being the proven reliability of L5P rotating assemblies especially when running bigger injectors, turbos etc. The other MASSIVE gain is the side draft intake design in the L5P heads. Even porting the intake as big as you can go with LML intake ports are no comparison to the massive airflow capability of the L5P intake. This is especially prevalent with s400/compound setups.

Diamondback Diesel’s plan to provide kits for these is still not fully finalized but as of now we are planning on offering kits where the customer would provide their own short block and will need their own air and fuel. We will provide all custom parts with the exception of a few mods needing to be done to the block. There will be detailed instructions on every aspect. This is a swap that will require a bit of a higher skill level and it’s recommended that a reputable and competent shop to install this kit.
We are currently working with many different manufacturers to make a lot of our custom parts on larger scale to make production of these kits fast and efficient.
As of today 05/12/2026 there is only one in existence but we have more on the way for testing purposes and are also looking for more shops willing to test this setup and report back your findings!

Huge thanks to Dominic Ferrante at Density speed and performance for absolutely killing the tune and getting this truck dialed in at 718WHP! Dyno video in the comments!

05/12/2026

Alright the wait is over! There was some good guesses and intuitive thoughts about what we had cooked up under the hood of our tow rig in the last 2 posts but I’ll stop teasing everyone and finally announce what we’ve created! We have successfully engineered the first ever L5L DURAMAX!! The ultimate solution for all the LML owners sick and tired of breaking cranks and cracking pistons or for the guys that want a monster of a motor for their high HP activities! To keep it short and sweet it is a COMPLETE L5P long block (block rotating assembly, heads and valve covers and intake manifolds) but it is fueled by LML injectors and run completely off of LML electronics/computers. I want to keep this one post kind of short but I will post a link in the comments to our explanation post and our plans with providing kits for anyone interested in installing an L5L in there 2011-2016 Duramax!

Please SHARE SHARE SHARE!!! Keep your eye out for our next post giving a little more detail about the motor and what our plan is to help you get yourself an L5L in your truck!

As a Duramax ONLY shop we are your go to one stop shop for all your performance and repair needs!

05/11/2026

05/11/2026

You guys are getting close! Here’s a few more to help you figure out what might be happening under the hood of this beast! Next post will fully reveal it!

05/11/2026

We got our 2015 tow rig’s new motor broken in and running great! Very happy with this setup! Can you spot the oddity?? More to follow…

10/19/2024

We have an LBZ/LMM Budget short block going together that will be up for grabs next week! Who’s in need of short/long block!
Our standard budget build comes with,
LB7 crankshaft keyed and polished
LBZ connecting rods
LB7 pistons
LBZ keyed camshaft
Fully balanced rotating assembly
Magnafluxed, shot blasted and decked LBZ/LMM engine block
Brand new GM lbz oil pump
Brand new GM L5P oil cooler
All mahle H series bearings
Mahle piston rings
Mahle gaskets all around
Full reconditioned cylinder heads with new valve seals and full valve job (long block only)
All covers installed and powder coated with DBD colors (can do custom colors as well)
Brand new GM oil pressure sensor and relief valve
1 year warranty
Rated at a conservative 600HP!

Starting at $8,500 for a short block

$11,750 for a long block with valve covers installed

Shoot us a message if you need a Duramax engine!
We can build any engine you’re looking for including 1000HP+ competition engines!
We have lots of used parts available as well!

09/22/2024

The rainy day has us in the shop wrapping up a fresh Budget build reman for a customer here in illusion purple!

This will be going in a 2012 LML Duramax with a brand new exergy sportsman CP3 to get rid of the ticking time bomb CP4!

Our standard budget build long block is a nice upgrade from the factory LML internals sporting all new Mahle bearings and seals, keyed and polished LB7 crankshaft, LBZ/LMM rods, LB7 pistons, L5P oil cooler, brand new GM oil pump and lots more!

Shoot us a message with all your Duramax engine rebuild needs and our BRAND NEW line of turbochargers!

09/14/2024

As we have grown we have now out grown our old shop and Diamondback Diesel has moved! Just down the road though!

We have moved to a bigger facility with much more shop space and we now have an official Engine/turbo building shop!

We build anything from stock budget builds to full competition motors!

Message us for quality products to keep your Duramax on the road with reliable parts and workmanship! Our line of performance turbos pair nicely with our line of mild to wild short/long blocks!

09/14/2024

Diamondback Diesel is excited to announce our new line of DBD turbochargers!

We are offering stage 1 and stage 2 turbos for all 2001-2016 Duramax engines!

All our turbos are built with quality parts exceeding OE standards to help push your Duramax to the next level!

All turbos come standard with a 1 year unlimited mileage warranty!

All turbos comes with a brand new remote oil feed line and drain tube!

All turbos are built with all NEW parts although we may be offering a reman service in the future!

We also offer powder coating on the front cover for additional $99! Any color of your choosing!

Starting at $2199 for 04-16 units

Website will also be coming soon!

17+ Turbos will be available in the future!

Shoot us a message or give us a call for all your Duramax needs!