[Editor’s Note: This L96 engine upgrade guide is part of a series of LS engine upgrade guides assembled by a team of LS experts at Summit Racing that we are sharing at OnAllCylinders. For a primer on the entire LS engine universe, read LS Engines 101: An Introductory Overview of the Gen III/IV LS Engine Family.]
Intro to L96 Engines
The L96 engine came in Chevy and GMC 2500 and 3500 HD series trucks, vans, and full-size SUVs from 2010-2017. It was a replacement for the LY6 with added flex fuel capability.
It’s the next best thing to an LSX block when it comes to adding boost or nitrous.
The rugged iron block 6.0L came with VVT, but without Active Fuel Management, which saves you the cost of an AFM delete kit.
You also get the sturdy 4th-gen full-floating connecting rods and a boost-friendly 9.6:1 compression ratio. Most 6.0L truck engines came with cathedral-port heads. The L96 (along with the LC8, L76, and LY6) came with high-flowing LS3-type rectangle port heads.
These engines start life in trucks, but today you’re just as likely to spot them under the hood of a turbocharged drag car.
Because of their strength, these engines are great candidates for power-adders.
[Every engine spec you’ll need can be found here: L96 Engine Specs: Performance, Bore & Stroke, Cylinder Heads, Cam Specs & More.]
How to Get More Power From Your L96
For many people, upgrading an L96 starts with adding a cold air intake and aftermarket exhaust. This will definitely free up a few horsepower and the V8 burble will make your ride the center of attention at a stop light.
Trucks often come with mechanical fans that sap horsepower. An electric fan kit will free up that power.
These mods can be done in your garage, but the tune won’t be optimized.
We recommend that you talk to your local chassis dyno tuner and decide on a computer programmer.
Whether you’re towing on low-octane or springing for good fuel, a tuner can dial the ECM and take it to the next level. Raising the factory redline is a big part of this because it allows your vehicle to be in the meat of the powerband longer.
Torque limiting can be completely shut off, shift points can be raised, and it makes it easier to tune for a bigger cam and injectors later on. Before beginning the tuning process, we recommend installing a colder thermostat to open up the L96 tuning window.
Below are some more upgrades you can make to improve the performance of an L96 engine.
Upgrading the L96 Camshaft and Valvetrain
At 196° of intake duration and .467 in. lift, the L96 cam isn’t a bad choice for people using AFM delete kits who want to maintain the stock idle and tune. But that’s not why you’re here—so read on!
VVT is great in a street car if you install a VVT cam and phaser-limiter along with a tune. If you don’t want to mess with it, you can easily convert to a standard non-VVT one- or three-bolt cam.
[Read LS Tech: How to Delete Variable Valve Timing (VVT) on an LS Engine for more info and part numbers.]
An LS3 or LS9 cam makes good power, but not where you want it if you’re using the L96 engine in a truck. What you need is a cam that delivers a gut-punch right when the converter hits. We recommend a dedicated truck cam.
If the engine is going in a lighter car with deep rear-end gears and a high stall converter, you can be more aggressive with duration.
What’s the difference?
To maximize torque in the mid-range in a truck cam, manufactures close the intake valve at about 35-40 degrees (@.050 in.) after bottom dead center and alter the intake valve opening to set the idle quality.
The 6.0L engine can take a little more cam than a 5.3L and still idle well.
What if you already have a power adder?
Generally, supercharger cams and nitrous cams will have slightly more lobe separation and longer exhaust duration. Turbo cams reduce overlap with less exhaust duration split in relation to the intake.
|Intake Duration (@ 0.050 in.)||Horsepower at the wheels after bolt-ons||Idle Quality||Notes|
|196° (Stock)||300-325 whp||Smooth||Heavy drivetrain.|
|215°||+50 hp||Slightly noticeable||Good with auto and stock converter.|
|220° - 230°||+75 hp||Steady lope||Converter recommended. Still can drive daily.|
|230° - 240°||+100 hp||Lopey||Fly-cutting the pistons may be required. Heads and intake good for another 50+ hp.|
Drop-in .500-in. lift cams are popular, but LS6 springs allow you to run .550-in. lift and extend the rpm range. Spring life isn’t a problem because trucks generally don’t spend a lot of time at high rpm. Beyond that, .575 to .600 in. isn’t a problem with dual valve springs.
The stock rockers are good up to 175 lbs. of seat pressure and 450 lbs. open. You will want to install a trunnion kit for added reliability.
There are a few other parts needed for a L96 cam swap such as an LS2 timing chain, LS7 spec lifters, LS2 timing chain damper and thick-wall chromoly pushrods.
L96 Power Adders
In general, an L96 upgrade will involve adding boost or nitrous before starting any serious work on the cylinder heads.
Before we get into the power adders, there are a couple of things to address:
- A 4-corner steam kit reduces hot spots that cause the rings to butt and snap the piston’s ring lands.
- Any power will put you well past the limitations of the early injectors. We’ll address those in the next section.
Okay, here’s the fun stuff:
- A nitrous oxide kit (at low settings) is great for street driving with stock internals. Up to a 200-shot is common. If you’re wanting to get serious, a single plane intake is less prone to break from a nitrous backfire. A plate system has better distribution than the original intake, but an eight-nozzle fogger system is even better. Running higher octane fuel is advised.
- Truck engine bays make fitting turbos easy. Single turbo systems using turbo exhaust manifolds are an inexpensive way to make big power. If you’re running a single turbo, the T4 hot-side fits well, but the small turbine diameters limit exhaust flow. The 650 whp begins to feel like 400 did in a hurry, so take this into consideration. V-band style exhaust housings are available with larger turbines and make plumbing easier. Although twins are a little more expensive out of the box, you’ll have more room to grow.
- A roots-style supercharger is dependable and makes great torque in the low- and mid-rpm range. It’s great for melting tires.
- A centrifugal-style supercharger is lightweight and makes more power at high rpm. This is partially due to a larger intercooler mounted in front of the radiator.
Upgrading the L96 Fuel System and Tuning
The flex-fuel engine injectors are pretty good to start and rated at 50 lbs. GM through some other goodies in to make them compatible with E-85. Stainless fuel rails, SIL-1 nitrided intake valves, and Brico 3010 valve seats were standard.
The factory pump and injectors are good for about 550whp from the factory.
In-tank fuel pumps and external pumps are popular, but mild fabrication will be required. Other options to maintain or increase pump pressure include electronic voltage controllers and hotwire kits.
When running boost, you can use a water-methanol system to supply extra fuel and lower charge air temps.
One last note on tuning: The L96 has a 58x reluctor ring and isn’t compatible with the early ECMs. It’s best to keep the E38 ECM as it’s faster and tunes better with bigger cams.
Upgrading the L96 Intake Manifold and Throttle Body
If you have a power adder, the intake and 87mm throttle body can take a backseat for a while longer.
The factory truck-style manifold has long runners for better low-end torque and makes good power from idle through 6,000 rpm. It’s also very good for boost.
Porting the intake is an option and a good value.
If you have the L96 in a vehicle with deeper gears, bigger converter, cam, and the rev limit bumped, you may want to trade a little of that low-end torque for some top-end horsepower. If so, go with a tunnel ram. Gains of 35 whp are possible with the crossover point starting at around 5,500 rpm.
Ask your tuner about going with a speed density tune. Doing so will remove the MAF restriction and will give you a bit more power.
[Trying to find an LS or LS-based Vortec engine for a swap or build? Check out Part 1 and Part 2 of our LS Spotter’s Guide.]
Upgrading L96 Cylinder Heads
The L96 cylinder heads are similar to the LS3 heads, and make good power.
- The stock heads can be CNC-ported for more airflow and milled up to .030 in. for more compression. Flow numbers can be as high as 373 cfm at .700 lift. Lightweight hollow stem LS3 valves will drop right in. Between the light valves and better springs, the engines will pull cleanly to 7,000 rpm. Keep in mind, if you’re looking to boost to 800+ hp; a heavy duty aftermarket stainless intake valve is a bit tougher and won’t tulip as quickly from the heat.
- A better option is aftermarket heads. They reduce down time, they’re all-new, and you can usually offset the added cost by selling your original heads. Valve angles are typically laid over to 13.5 degrees. They flow better and the cross-sections are great for naturally aspirated or boosted engines. When comparing heads, look at the .400 in. lift numbers as a general indicator of how the heads will perform. With a medium-sized cam, 475+ whp naturally aspirated is common even with the heavier truck drivetrain.
Upgrading the L96 Rotating Assembly
On the L96, the pistons are the weak link and you probably know a guy that’s popped one.
A set of forged pistons should be high on your priority list.
They have stronger wristpins, thicker ring lands, and the added valve reliefs allow you to run big cams. If you’re going over 800 hp, a set of .200 in. wall tool-steel pins is a good idea.
The L96’s Gen. 4 rods are stronger than the Gen. 3 rods and have full floating pins. They can handle about 800 hp and 7,000 rpm in boosted applications (at least for a while). They are likely to bend before they break when subjected to real track conditions.
If you’re getting forged pistons, upgrade to forged connecting rods at the same time. Big 7/16-inch rod bolts will go a long way to keep things together over 7,000 rpm.
The L96 crank was cast but strong. They’ve been known to handle over 1,000 whp.
The main reason for going with a stroker forged crank is for the added cubic inches. The extra cubes bring boost on quicker which means you can use bigger and more-efficient turbos.
Performance rotating assemblies are available in many combinations.
A few notes of caution:
- The 6.0L iron blocks had shorter cylinder sleeves than the aluminum blocks (5.430 in. vs. 5.500 in. on average). Much of the piston skirt drops out of the bottom of the cylinder at BDC. The best piston manufacturers have compensated for this by eliminating skirt taper until a point well above where it meets the bottom of the cylinder sleeve at BDC. Any skirt taper at this intersection acts as a razor blade and will wear out the piston quickly.
- The blueprint deck height of the block is 9.240 in., but it’s common to find them in the 9.230-in. range. It’s best to measure deck height before ordering your rotating assembly. Thicker head gaskets or using an aftermarket 6.098-6.100 in. rod will ensure enough piston-to-head clearance.
|Engine Size||Bore Diameter||Piston Comp. Height||Stroke||Rod Length||Wristpin Diameter|
|4.000 in.||1.338 in.||3.622 in.||6.098 in.||0.9431 in.|
|4.030 in.||1.110 in.||4.000 in.||6.125 in.||0.927 in.|
Upgrading the L96 Engine Block
The L96 has a 4.000-in. bore diameter and can be safely bored to 4.030 in.
After that, it’s recommended to hone in .010 in. increments with successive builds. Having your machine shop sonic check your block is a good idea.
You can make 1,000 hp with a couple of simple upgrades like head studs and LS9 head gaskets.
Four head bolts per cylinder aren’t optimal, but you can O-ring the block if you’re aiming for 1,000+ whp.
The factory main caps aren’t doweled. It’s better to reduce ignition timing and compensate with added boost to reduce the cylinder pressure spikes that lift heads and cause the main caps to dance.
Main studs should be added anytime you’re this deep in the engine.
The blocks have been known to withstand 1,300+ whp with proper machining, racing fuel and an excellent tune.
(Information for this article originally appeared in the “Upgrading the Gen. 4, 6.0L, Iron Block, LS Truck Engines” article at Summit Racing’s searchable database of FAQ tech info. Go there and search “LS engines” for a comprehensive collection of LS engine tech information.)
NOTE: You can find engine specs and detailed engine upgrade advice for every LS and LS-based Vortec truck engine in one place: The Definitive Guide to LS Engine Specs and LS Engine Upgrades.
I have a 1984 GMC K-1500. Would this engine fit in my truck? Also, what additional expense would be incurred with swapping from my current 350 engine?
Therw is not 1 simple answer……need ECM and wire harness….mounts and trans adapter….if going to carburated set up therw are LSX control units to run it. I would stay fuel injected because tuning is more precise…Speartech Fuel Injection has lots of harness options also Painless wiring has swap harness too……DO YOUR RESEARCH cause therw are infinite options. Going into a square body makes things easier though. I would look for an L96 GEN 4 6.0L VORTEC from 2500 3500 Vans and truck from 2011-2017… WAY BETTER STARTING POINT than a wimpy 5.3l especially in a truck…GO 6.0L U wont regret it.
This article is excellent, very informative. Thanks
I’ve bought a 2019 Chevy 2500 cargo van with the 6.0 liter engine, was wondering if that engine has a cast iron block
Yes it does have a cast iron block.
Yes, its the exact motor they are talking about in the article. L96 6.0L Also the trans that came behind that motor is stout as well 6L90-E and is strong as f*** I would just upgrade the converter and toy will have a bad ass transmission.
Last year for the L96 engine was 2017 so no a 2019 is not an L96….google it, multiple sources….
The L96 is still available in 2020 express vans. Wikipedia and many other online sources do not have the correct information. Go to gm.com and you can spec build one today.
Mounts harneas and ECU .SPEARTECH FUEL INJECTION SYSTEMS HAVE NICE HARNESSES READY TO GO
Towing an 8800lb. toyhauler. Have a 2015 6 liter Chevy 2500. Need a little more horsepower. What do you recommend the next step to be? Headers and larger diameter exhaust?
Towing a 8800lb. Toyhaulers with a 2015Chevy 6.0 liter
L96. Needs a little more horsepower. What do you recommend the next steps to be..
I’m in the same boat. Fully loaded toy hauler is 7,500lbs. My 2019 6.0l is dogging. Just need a touch more power.
Did you ever get any answers, anywhere?
Did you try exhaust yet? Intake?
I’m 100% totally stock California emission to boot, but I live in Nevada.
Same here with my 2016 2500HD. I installed a K&N cold air intake. Also increased the diameter of my exhaust 0.5 inches everywhere rear of the CAT and performance muffler. Then I bought a Diablosport Trinity 2 tuner. Runs great on E85 but also consumes more fuel on E85. The added performance from these three easy upgrades was very noticeable and exciting at first, but now I’m looking for a little more.
Get a custom cam made exactly for what your doing by Martin Smallwood at TICK PERFORMANCE. If you need massive torque for towing he will make you the best cam for that application. He is the Cam Whisperer.
I would get a set of cheap ebay 1.75″-2.5″ Long tube headers($200-300), LS6/LS3 springs($45-70) or Pac1218s ($100-150), a 216/220 .560/.560 114 Elgin cam($125-200), 2.5″ dual true dual exhaust($200-300), summit 2.5″ dual in/dual out muffler($50), 160-180 tstat($35-50), NGK tr6s ($12-25), then a good dyno tune ($400-700)
good morning, I bought an engine l96 to change my truck and they sold me a controller kit for that engine number 19417415 but that kit does not bring connection for automatic transmission that I have a 4L80E, and the truth is that I don’t know what to do you can help me, Why was I finding out and they tell me to put a transmission controller kit number 19302410 to work for me, but my Harness kit or my ECM doesn’t have any extra connection to connect that controller, maybe I have to change something? Thank you, I’m looking forward for your answer.
Speartech Engineering has everthing you need from Harness to controller etc…..high quality stuff too.
are the 2010 to 2017 the same to a 2019 ?
Google GM Vortec engines wikipedia. It will give you a rundown of everything
Hi I just bought a 2019 2500 6.0l. I do tow a few times a year, and would like more torque; even a little would help. What can I do without “pushing” the motor or the warranty too hard?
Intake and exhaust?
Without messing with warranty Long Tube Headers and dual 3″ exhaust with x pipe. Cold air intake…a good one thats sealed..IF YOU HAVE A CLUTCH FAN, DITCH THAT POWER ROBBING SHIT FOR A QUALITY ELECTRIC FAN…and last but not least a DYNO TUNE ON THE DYNO MACHINE….NOT A GENERIC PROGRAMMER. THIS WILL EASILY GIVE YOU 30 TO 40 HP AND EVEN MORE IF YOU CAN RUN E85 FUEL. DONT GET HUNG UP ON NUMBERS ITS THE POWER IT MAKES UNDER THE CURVE IS WHERE IT REALLY SHINES AND YOU CAN FEEL IN THE DRIVABILITY.
Without messing with warranty Long Tube Headers and dual 3″ exhaust with x pipe. Cold air intake…a good one thats sealed..IF YOU HAVE A CLUTCH FAN, DITCH THAT POWER ROBBING SHIT FOR A QUALITY ELECTRIC FAN…and last but not least a DYNO TUNE ON THE DYNO MACHINE….NOT A GENERIC PROGRAMMER. THIS WILL EASILY GIVE YOU 30 TO 40 HP AND EVEN MORE IF YOU CAN RUN E85 FUEL. DONT GET HUNG UP ON NUMBERS ITS THE POWER IT MAKES UNDER THE CURVE IS WHERE IT REALLY SHINES AND YOU CAN FEEL IN THE DRIVABILITY. Good headers will make torque under the curve…dontt cheap out on headers…
Just got a L96 with its E78 pcm from a 2500 Silveraldo. Its going in my K5, but I am having a heck of a time figuring out the harness issue.. I was planning on thinning it out myself but am finding very little info on doing that. The LT1 site does not have any info on it either . All i find is aftermarket harnesses. I am trying to keep it a budget build.. picked up the long block for 600 and a 4l60e for 200. So was hoping to follow some directions and put some time in doing the harness myself rather than spending $800++++ on a harness.
Do you have any resources on this?
Should/could I just run an older harness and PCM?
Any info would be greatly appreciated!!
Speartech Fuelinjection sustems…… Google
Painless Wiring Harnesses
Pailess makes a nice harness too
What brand long tube headers do you recommend? What brand good quality electric fan do you recommend?
Can we please get an answer on a long tube header that would work for a 2019 2500HD gas 6.0 liter? I’m having trouble finding any, because the search engine is assuming the 2500 is a diesel.
Stainless Works can make you a set and Kooks as well. Sorry for delay have been busy as heck…
[…] [Looking to upgrade your L96 engine? Check out L96 6.0L Engine Upgrade Guide: Expert Advice for L96 Mods to Maximize Performance.] […]
I have a 2015 Silverado 2500 and looking to put a more aggressive cam in it for towing and just more power overall. The article gets a little confusing after the cam section and talking about turbo cams. It also lists other parts needed for cam swap like push rods, etc.. is all of that necessary with a drop in mild cam like a SUM-8701?
Try the Elgin 216/220 .560/.560 114,you can use it with cheap blue or yellow LS6/LS3 springs or pac 1218s. If you’re using Pac1218s, comp 918s or the Howard’s equivalent .650 lift single springs there is also the Elgin 220/224 .575/.575 112 or 228/230 .585/.585 112 all have been showing up on Ebay and Amazon from $100-200.On a 6L with rectangle port or 706 heads even the big 228/230 had no to loss through the curve, a swap to 706 heads and a tbss intake on a 6L would increase low and mid rpm to significantly and only lose a small amount of peak hp if any in a truck rev range up to 6500rpms.
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Hi there, I bought a 2013 L96 with 40,000 miles on it, when the motor was pulled from truck the tarp deteriorated and we got water on a couple cylinders there is very light rust on the cylinder walls everything looks brand new inside the engine as far as cam and bottom end. I’m on a budget but I would really love to just use what I have and put a comp cam in it . Do you think I can Hon cylinders to remove rust and just re-ring the pistons or what do you think the safe thing would be to do not going three huge build since the motor only has 40,000 miles on it thank you , Thomas H.
Did every upgrade you describe, including a Whipple super charger, forged rotating assembly stroked to 6.8l of coarse. In have 595hp at the rear wheels tuned. I need a recomendation for a new torque converter as my seems to not perform well on full throttle acceleration.
I have a 2013 Chevy 2500hd with the 6.0 vortec. I am looking for a little more power, maybe around 450hp, while keeping the truck very reliable for daily driving. I tow a decebt bit and wanted a way to get a little more power. Any ideas?
Can you confirm that the L96 engine can be used as a replacement for 1997 GMC 1500 Truck? What if any CA Emissions issues would be involved in this upgrade ? Current engine is 5.7L. I understand an updated Transmission may also be needed but first need to know if the L96 can be used in a CA Truck.
Thank you !
I have a 2015 Chevy 3500 Dooley flatbed I have broken lifters what all parts do I need to rebuild the truck I want it to run like a Ss V or at least sound like one