Considering L96 6.0 Swap - Initial questions

[DaveO9]

I'm in the very preliminary stage of planning an LMG 5.3 to L96 6.0 swap for my '13 Tahoe. I'm hoping to move on this sometime this coming winter or spring, but it could be a year from then, too. Rig has 210k with AFM tuned out. Runs good now, but I think I'm starting to hear a little lifter tick at hot idle. Plus, would like some additional power for hill climbing with my travel trailer. My plan would be to keep the 6.0 internally stock and just replace things like oil pump o-ring, pan gasket, etc. A few questions to help me plan...

1. y-pipe. Do I need to upgrade from the 5.3's? I think the tubing on a 6.0 equipped Silverado is bigger? Should I look for a y-pipe from a 6.2 SUV? I will upgrade the rest of the exhaust to at least 3" with an aftermarket muffler.
2. Cooling. Do I need to to do any upgrades? I've replaced most of the cooling system on this rig, including a Denso 2219514 radiator.
3. From researching other threads, sounds like I will use my OEM ECM. I have a local tuner that I've trusted for years - I will be checking with him to see if this is within his ability. He's the one that tuned out my AFM, provided a basic engine and trans tune, eliminated lock up in 4th and lower, re-tuned for my GR swap, etc. Do I keep injectors from the 6.0? I've seen it both ways.
4. Trans and converter. Not really in the budget for any major trans work. I know that something will need to be done sooner or later and the 6.0 will only hasten that, but.... Zero trans issues now. I don't think it ever towed anything in its life before I got it. That all being said, should I upgrade the converter at this point?

 

[swathdiver]

I'm in the very preliminary stage of planning an LMG 5.3 to L96 6.0 swap for my '13 Tahoe.

1. I plan to. The 2011+ Y-Pipe for the 6.2s is a three cat design with 3.5" pipes. The earlier 6.0-6.2 design was 2.75" with 2 cats if memory serves, and a flange instead of band connection to the exhaust.

2. The 2500 SUVs use a different radiator as do the 1500s with the 6.2. I plan to change mine to the 6.2 radiator, 21648 or 22840115.

3. Keep the donor engine's intake and fuel rail and injectors, they're larger than the 5.3s and may have physical different lengths.

4. Up to you. You could at least replace it with a stock reman and change the lockup clutch o-ring on the shaft.

 

[j91z28d1]

for injectors, I just kinda looked up some of this for another car. the flex fuel injectors are(edit) 58lb hr and a good cheap swap for other cars as well. I'm running them in my ls3 car as they are larger than the stock ones. which one went bad, so took the time to upgrade incase I want to run e85 later on it.

if either engine, but most likely your 5.3 if flex has part number 12613412 injectors. keep them, they will easily make 500hp before needing bigger. as for the tune, if it's not already in the tune, in hptuners just put in the easy to fine injector data for them and good to go tune wise and then just adjust like normally for the rest as normal. mostly just copy and paste timing and maf table from the 6.0 tune and data log to make sure it's correct.


my 2 cents is do the new torque converter while the engine is out. it might save you a full tranny rebuild which is very expensive these days. and they have a habit of going out at all the wrong time.

 

[DaveO9]

1. I plan to. The 2011+ Y-Pipe for the 6.2s is a three cat design with 3.5" pipes. The earlier 6.0-6.2 design was 2.75" with 2 cats if memory serves, and a flange instead of band connection to the exhaust.

2. The 2500 SUVs use a different radiator as do the 1500s with the 6.2. I plan to change mine to the 6.2 radiator, 21648 or 22840115.

3. Keep the donor engine's intake and fuel rail and injectors, they're larger than the 5.3s and may have physical different lengths.

4. Up to you. You could at least replace it with a stock reman and change the lockup clutch o-ring on the shaft.

Thanks, James. All good info, will help me with planning. So you’re planning this same swap?

for injectors, I just kinda looked up some of this for another car. the flex fuel injectors are 42lb hr and a good cheap swap for other cars as well. I'm running them in my ls3 car as they are larger than the stock ones. which one went bad, so took the time to upgrade incase I want to run e85 later on it.

if either engine, but most likely your 5.3 if flex has part number 12613412 injectors. keep them, they will easily make 500hp before needing bigger. as for the tune, if it's not already in the tune, in hptuners just put in the easy to fine injector data for them and good to go tune wise and then just adjust like normally for the rest as normal. mostly just copy and paste timing and maf table from the 6.0 tune and data log to make sure it's correct.


my 2 cents is do the new torque converter while the engine is out. it might save you a full tranny rebuild which is very expensive these days. and they have a habit of going out at all the wrong time.

Thanks, good fuel injector info. Yeah I’ve seen some threads where the advice was to run the 5.3’s injectors. Mines flex fuel, so sounds good.

My tuner use Tuner Cats, not HP, but it still sounds pretty doable. Just swapping out some of the tables and parameters.

 

[swathdiver]

Thanks, James. All good info, will help me with planning. So you’re planning this same swap?

Yes, will probably take longer than the axle swap! I don't want to do anymore work at this house, want to get one with a shop or bigger garage.

L9H injectors are 54 lbs @ 58psi. The FlexFuel pump will handle about 500 rear wheel horsepower on gasoline.

 

[Charlie207]

When I swapped my 5.3 LMG for a 6.0 LY6 I did the following:

- reused my existing exhaust manifolds and y-pipe. (have since upgraded to long-tubes and 3.5" y-pipe, although BBP states 3" is more than enough for any N/A engine.)
- replaced the factory JMBX torque converter with the >$300 billet unit from Summit Racing.
- kept the LY6 fuel rail, but swapped in the LMG injectors. (per BBP)
- swapped the LMG MAP sensor into the LY6 intake manifold. (per BBP)
- needed a cam sensor adapter: OEM 5-wire to LY6 3-wire, as I deleted VVT to use a upgraded cam. You won't need that if you keep VVT.
- Cooling: I already have the K5L package, so I left all the cooling alone, but replaced the TOC lines with new ones.
- I used the LMG starter motor, as the LY6 was slightly different, and older.


I wish I had just sent it with the new headers and y-pipe at the time of the engine swap, as it would have saved me about a day of futzing around a year later. Also, I might recommend using exhaust manifold studs instead of new bolts. It makes like easier if you decide to swap manifolds for headers later on.

 

[mikez71]

What are the downsides to a 6.2 vs the 6.0?

It sounds like the 6.0 are used in more heavy duty vehicles, but the 6.2 has a bit of extra power.
I have heard of piston slap, worn cam journals, and dropped valve seats on the 6.2.

Any other reasons to go with the 6.0 over the 6.2?

 

[Charlie207]

What are the downsides to a 6.2 vs the 6.0?

It sounds like the 6.0 are used in more heavy duty vehicles, but the 6.2 has a bit of extra power.
I have heard of piston slap, worn cam journals, and dropped valve seats on the 6.2.

Any other reasons to go with the 6.0 over the 6.2?

I have no clue really. I've always heard the anecdotal jabs that a 6.0L is a "truck engine" and the 6.2L is "car engine in a truck".

Does that make sense??? who knows, but there's probably a benign reason why the 6.0 was put in all the HD trucks.

EDIT: My guess is better tolerance of heat under prolonged, heavy, load. Iron block 6.0 vs. aluminum 6.2.

 

[mikez71]

Thanks, makes sense.
Just noticing 6.2 is aluminum, and cam has more lift than 6.0 also.

 

[Marky Dissod]

What are the downsides to a 6.2L vs the 6.0L?
It sounds like the 6.0L are used in more heavy duty vehicles, but the 6.2L has a bit of extra power.
I have heard of piston slap, worn cam journals, and dropped valve seats on the 6.2L.

Any other reasons to go with the 6.0L over the 6.2L?

6.0L would be a better bang for the buck.
Demographically, I'd bet most 6.0L were worked hard, but more likely to be maintained similarly;
vs the 6.2L being more likely driven 'enthusiastically' but less likely to be maintained enthusiastically.

Physically, I'd not be surprised if the 6.0L provided comparable torque / throttle response under 2400RpM
compared to the 6.2L; obviously the 6.2L shines after the downshift & the RpM climbs.

I get that this is a Gen4 V8 conversation, but I maintain that, if one is to delete VVT on a 6.0L
might as well research which heads (862-706 holy or 799-243 holy) vs which piston (dishes) will yield 10.4:1 - 10.7:1 scr (without going over).
Still haven't figured out which GM OE 4.00" bore head gaskets yield the best quench ...

... always heard anecdotal jabs that a 6.0L is a "truck engine" and the 6.2L is "car engine in a truck".
Does that make sense??? who knows, but there's probably a benign reason why the 6.0L was put in all the HD trucks.

EDIT: My guess is better tolerance of heat under prolonged, heavy, load. Iron block 6.0L vs. aluminum 6.2L.

Every Gen4 6.2L V8 is a detuned LS3 (question is 'detuned to what extent'?),
then some got Variable Cam Timing and/or E85-ability and/or Engine Half@$$.
Iron Block 6.0L got lower scr (9.4:1-10.0:1), Alum Block 6.0L got higher scr (10.4:1 - 10.7:1).

My goal would be to 'build' a 10.4:1 - 10.7:1 scr 6.0L, mix'n'matching various GM OE parts,
to wind up with a 6.0L V8 that makes the L92/L9H/L94/L99 look silly under 4250RpM;
basically my version of an LS2 (which makes about as much power as any 6.2L that is not an LS3).

 

[j91z28d1]

a 6.0 can have either style port head right?

I think the iron 6.0 with cathedral would make a better truck motor for shooting for 500k miles and tow work on 87


I would still look for a part out hybrid. aluminum 6.0 cathedral head for cheap haha.

 

[Charlie207]

a 6.0 can have either style port head right?

I think the iron 6.0 with cathedral would make a better truck motor for shooting for 500k miles and tow work on 87


I would still look for a part out hybrid. aluminum 6.0 cathedral head for cheap haha.

From what I've seen, the Gen3 engines use a cathedral-port head, and the Gen4 engines use the rec-port heads.

I've seen conflicting opinions on which style is "better", so IDK. I've also been keeping my eyes open for the hybrid 6.0s for a cheap rebuild, but really, it's just a 100lb. savings.

 

[j91z28d1]

From what I've seen, the Gen3 engines use a cathedral-port head, and the Gen4 engines use the rec-port heads.

I've seen conflicting opinions on which style is "better", so IDK. I've also been keeping my eyes open for the hybrid 6.0s for a cheap rebuild, but really, it's just a 100lb. savings.

I see stuff like this all the time around here.

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but you're right, with a truck a 100lbs isn't really anything. in a car a ls2 is a big deal. you might make more money selling it as a ls2 haha.

gm used cathedral heads on the Gen 4 hybrid. but I can really only guess why. my logic would say tq at 1500-2000 rpm. as that where mine seems to live it's life around town but then again, wot at 2k vs. Just part throttle around town

 

[Charlie207]

I see stuff like this all the time around here.

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but you're right, with a truck a 100lbs isn't really anything. in a car a ls2 is a big deal. you might make more money selling it as a ls2 haha.

gm used cathedral heads on the Gen 4 hybrid. but I can really only guess why. my logic would say tq at 1500-2000 rpm. as that where mine seems to live it's life around town but then again, wot at 2k vs. Just part throttle around town

People get hung up on the "what hp/tq at what RPM" talking points, but avoid the reality that the transmission will kick down a gear or two, to put the engine in the optimal zone. I'm sure with the addition of transmission ratios over the time, the slight benefit of a little >2000rpm TQ went away.

 

[Marky Dissod]

People get hung up on the "what hp/tq at what RpM" talking points, but avoid the reality that
the transmission will kick down a gear or two, to put the engine in the optimal zone.

A 5.3L trying to do the same work in the same elapsed time, will likely downshift more often than the 6.0L,
if the transmission / tcm is tuned to compensate for the 5.3L's lack of low-RpM strength.
Interestingly, the LFA / LZ1 6.0L made less low-RpM torque than other 6.0L
because the Atkinson-cycle cam was meant to depend on hybrid electrical assistance.
In other words, upgrade from and be ready to dispose of the LFA/LZ1 cam.

I'm sure with the addition of transmission ratios over the time, the slight benefit of a little >2000RpM torque went away.

4L60 First gear: 3.06 ... 6L80 1st gear: 4.03 ... 8L90 1st gear: 4.56 ... 10L80 1st gear: 4.69.
10L80 2nd gear: 2.99 - in other words, if the 10L80 skipped 1st gear, it'd still 'leave' pretty much like a 4L60.
Transmissions with deeper AND wider gearing are why engines are getting smaller AND losing cylinders.

Fate forfend that automakers just make vehicles lighter ...

 

[j91z28d1]

oh yeah, use the hybrid cam for nothing. even dodge didn't use that style cam in their version of this hybrid. they went straight to normal hemi. only rated at one or 2 less mpg too.

 

[DaveO9]

I’m pretty set on a truck motor, L96, iron, stock cam and heads. Iron 6.0 should weigh about the same as my LMG. As for cost, from the little I’ve researched, L96 is going to be way cheaper and easier to get than a 6.2. I’ve seen L96 with 150k for around $2k, some I think even shipped.

I’d like to keep VVT, hence my desire for L96. Is only difference between L96 and LY6 flex fuel capability? If so, I could possibly expand my search - flex fuel doesn’t help much around here. I never see it at stations in WA and OR.

 

[Charlie207]

Is only difference between L96 and LY6 flex fuel capability?

I believe so, yes. I have no E85 pumps anywhere near me, so I didn't care about the loss of Flex-Fuel.

 

[DaveO9]

I believe so, yes. I have no E85 pumps anywhere near me, so I didn't care about the loss of Flex-Fuel.

Yeah, I took my first Tahoe ('09 Flex Fuel) on a rockies/midwest trip in 2023. I remember seeing E85 in at least a few of the states we went through: both Dakotas, Minnesota, Wisconsin, Iowa, etc. I think I even tried it out a few times on that trip. But I've never seen it anywhere in WA or OR.

 

[DaveO9]

When I swapped my 5.3 LMG for a 6.0 LY6 I did the following:

- reused my existing exhaust manifolds and y-pipe. (have since upgraded to long-tubes and 3.5" y-pipe, although BBP states 3" is more than enough for any N/A engine.)
- replaced the factory JMBX torque converter with the >$300 billet unit from Summit Racing.
- kept the LY6 fuel rail, but swapped in the LMG injectors. (per BBP)
- swapped the LMG MAP sensor into the LY6 intake manifold. (per BBP)
- needed a cam sensor adapter: OEM 5-wire to LY6 3-wire, as I deleted VVT to use a upgraded cam. You won't need that if you keep VVT.
- Cooling: I already have the K5L package, so I left all the cooling alone, but replaced the TOC lines with new ones.
- I used the LMG starter motor, as the LY6 was slightly different, and older.


I wish I had just sent it with the new headers and y-pipe at the time of the engine swap, as it would have saved me about a day of futzing around a year later. Also, I might recommend using exhaust manifold studs instead of new bolts. It makes like easier if you decide to swap manifolds for headers later on.

Which Y-pipe did you use? I'm thinking of one from a denali/escalade with 6.2. But am also wondering if one from a pickup with 6.0 would work.

When you refer to BBP, is that actually BRP Hot Rods? https://www.brphotrods.com/?srsltid=AfmBOoosYQgePMIA1hicggFy-DQNOxLD0RR3mWlguLtZYdUFQTxMWj9E