2008 Suburban Engine Swap - 6.0 to 6.2

strokersace

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New member trying to search and learn as much as I can in short time. So my apologies if I missed this swap already being covered. Most I see are a 5.3 to 6.2 swap. We bought our 2008 LTZ Suburban 1500 4x4 several months back and so far it's been great (minus the fuel economy). Factory optioned L76 6.0 with AFM & VVT, 4L70e trans, GT5 rear axle 4.10 gears, and G80 locking diff. It's mainly the family vehicle, grocery getter, and occasionally tow a little.

Last weekend on our way home from vacation, #6 misfire and stabilitrak went off. Noticeable lifter tick, rough idle, down on power, etc. Was planning on just rebuilding with AFM delete, cam, tune etc. HOWEVER, I just came across a good running L9H 6.2 from a wrecked 09 Denali about 45 minutes from my house for not much more $$ than the parts to fix the 6.0. Drop it in, tune with Blackbear, and go.

Thoughts? Anything I should do to the 6.2 before putting it in? Was thinking of just leaving the stock vvt cam in since it's already a non-AFM engine, but could be convinced otherwise. Was researching doing a 6L80 swap, but will be keeping the 4L70 for now. Same with axles, unless I can find a donor 14-bolt 3.42 along with front. The 6.2 does not have a flexplate on it. Can I use the one from the 6.0 along with the stock torque converter?

Been wrenching for a long time, mainly on the diesel side so not afraid of a custom setup. Just not much experience on the LS side of things. Any insight is much appreciated!!!
 

Geotrash

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New member trying to search and learn as much as I can in short time. So my apologies if I missed this swap already being covered. Most I see are a 5.3 to 6.2 swap. We bought our 2008 LTZ Suburban 1500 4x4 several months back and so far it's been great (minus the fuel economy). Factory optioned L76 6.0 with AFM & VVT, 4L70e trans, GT5 rear axle 4.10 gears, and G80 locking diff. It's mainly the family vehicle, grocery getter, and occasionally tow a little.

Last weekend on our way home from vacation, #6 misfire and stabilitrak went off. Noticeable lifter tick, rough idle, down on power, etc. Was planning on just rebuilding with AFM delete, cam, tune etc. HOWEVER, I just came across a good running L9H 6.2 from a wrecked 09 Denali about 45 minutes from my house for not much more $$ than the parts to fix the 6.0. Drop it in, tune with Blackbear, and go.

Thoughts? Anything I should do to the 6.2 before putting it in? Was thinking of just leaving the stock vvt cam in since it's already a non-AFM engine, but could be convinced otherwise. Was researching doing a 6L80 swap, but will be keeping the 4L70 for now. Same with axles, unless I can find a donor 14-bolt 3.42 along with front. The 6.2 does not have a flexplate on it. Can I use the one from the 6.0 along with the stock torque converter?

Been wrenching for a long time, mainly on the diesel side so not afraid of a custom setup. Just not much experience on the LS side of things. Any insight is much appreciated!!!
You have a unicorn. I've been on these pages a long time and have never seen a GMT900 Suburban with the L76. The L9H has flex fuel and no AFM, so you'll need to make changes to the fuel delivery parameters due to the FF (54 PPH for the L9H vs 42 PPH for the L76 ) injectors, and turn off AFM in the tune. Both engines are 58x reluctors, so your cam position sensor and the VVT system should connect right up as long as your L76 does indeed have VVT. I don't believe the car versions do, but the truck might. Both engines use the same heads, so should have no issues with swapping over your L9H injectors if needed. Other than these, I can't think of any reason why it won't work.

On the L9H, it's worth putting a new rear main seal and rear housing cover gasket on it, but the stock VVT cam is fine. If you're feeling fancy, then a larger VVT cam from Gwatney will give you a nice boot in the a$$, along with new springs and lifters, while you're in there. Also, definitely drop the oil pan and put a new o-ring on the oil pump pickup tube. Make sure the oil pressure relief valve in the pan has a deflector on it, and if it doesn't either install one or plug it. New water pump and thermostat of course. Might want to replace the valley pan gasket as well as the oil pressure sensor.

Oh, and check the driver's side valve cover to make sure it has the updated design on it for the PCV system.
 

diesel_dave

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Gonna agree with Geotrash on the suggestion to change most of the gaskets/seals while the engine is out and it is way easier to do. It will be the best couple hundred dollars you can spend as the ones that the engine has on it now are definitely getting close to the end of their useful non-leaking lives.
 

Geotrash

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Come to think of it, I would seriously consider putting in new valve springs regardless. Lots of L92 owners have has broken springs in the 150K plus range that caused problems like pistons arguing territorial rights with valves and both losing.
 

swathdiver

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New member trying to search and learn as much as I can in short time. So my apologies if I missed this swap already being covered. Most I see are a 5.3 to 6.2 swap. We bought our 2008 LTZ Suburban 1500 4x4 several months back and so far it's been great (minus the fuel economy). Factory optioned L76 6.0 with AFM & VVT, 4L70e trans, GT5 rear axle 4.10 gears, and G80 locking diff. It's mainly the family vehicle, grocery getter, and occasionally tow a little.

Last weekend on our way home from vacation, #6 misfire and stabilitrak went off. Noticeable lifter tick, rough idle, down on power, etc. Was planning on just rebuilding with AFM delete, cam, tune etc. HOWEVER, I just came across a good running L9H 6.2 from a wrecked 09 Denali about 45 minutes from my house for not much more $$ than the parts to fix the 6.0. Drop it in, tune with Blackbear, and go.

Thoughts? Anything I should do to the 6.2 before putting it in? Was thinking of just leaving the stock vvt cam in since it's already a non-AFM engine, but could be convinced otherwise. Was researching doing a 6L80 swap, but will be keeping the 4L70 for now. Same with axles, unless I can find a donor 14-bolt 3.42 along with front. The 6.2 does not have a flexplate on it. Can I use the one from the 6.0 along with the stock torque converter?

Been wrenching for a long time, mainly on the diesel side so not afraid of a custom setup. Just not much experience on the LS side of things. Any insight is much appreciated!!!
Burt Reynolds fan? LOL

Your plan is spot on IMO.

Check for oil leaks on the new motor, change the o-ring in the oil pump and as Dave said, consider some fresh valve springs. Then have it tuned by BlackBear to set up the ECM and TCM for that glorious L9H. You'll want to change the fuel pump assembly too, they are different between the motors. The Flexplates are the same, use your old one or just buy a new one.

Sounds like a fun project! You'll make some money back on selling the 6.0 too, they are sought after for LS swaps.
 

PatDTN

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Having dropped a 6.2 into my Tahoe you might want to consider the at least 60 cent a gallon difference between regular gas which runs fine in a 6.0 vs the required premium for the 6.2. There are plenty of threads in here about people trying to run less than premium in the 6.2.
 

PatDTN

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Oh and I wish I had worked out keeping VVT.
 
OP
OP
S

strokersace

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You have a unicorn. I've been on these pages a long time and have never seen a GMT900 Suburban with the L76. The L9H has flex fuel and no AFM, so you'll need to make changes to the fuel delivery parameters due to the FF (54 PPH for the L9H vs 42 PPH for the L76 ) injectors, and turn off AFM in the tune. Both engines are 58x reluctors, so your cam position sensor and the VVT system should connect right up as long as your L76 does indeed have VVT. I don't believe the car versions do, but the truck might. Both engines use the same heads, so should have no issues with swapping over your L9H injectors if needed. Other than these, I can't think of any reason why it won't work.

On the L9H, it's worth putting a new rear main seal and rear housing cover gasket on it, but the stock VVT cam is fine. If you're feeling fancy, then a larger VVT cam from Gwatney will give you a nice boot in the a$$, along with new springs and lifters, while you're in there. Also, definitely drop the oil pan and put a new o-ring on the oil pump pickup tube. Make sure the oil pressure relief valve in the pan has a deflector on it, and if it doesn't either install one or plug it. New water pump and thermostat of course. Might want to replace the valley pan gasket as well as the oil pressure sensor.

Oh, and check the driver's side valve cover to make sure it has the updated design on it for the PCV system.
It's the only 1/2 suburban I've ever been around with the aluminum 6.0. I thought it might have been swapped before, but got the build sheet from my cousin's dealership to confirm factory options. BTW, the truck version L76 does have AFM and VVT.

As for the L9H, one of the reasons I was drawn to it (besides already not having the AFM) was the higher psi injectors. Appreciate your's and @diesel_dave comments on the gaskets, o-rings, seals, etc., and at a minimum valve springs. The engine has around 150k and a good runner, but if I have it on the stand now's the time to do it like you guys mentioned. If I'm I'm opening it up at all, I'm highly considering a cam and doing lifters at the same time. Curious though (this is something I haven't researched much at all), you went with a non-VVT cam verses doing a larger VVT cam from Gwatney like you mentioned. Thoughts/reasons? I've been eyeballing the Gwatney stage 1 low lift vvt cam if I open it up that far.

Burt Reynolds fan? LOL

Your plan is spot on IMO.

Check for oil leaks on the new motor, change the o-ring in the oil pump and as Dave said, consider some fresh valve springs. Then have it tuned by BlackBear to set up the ECM and TCM for that glorious L9H. You'll want to change the fuel pump assembly too, they are different between the motors. The Flexplates are the same, use your old one or just buy a new one.

Sounds like a fun project! You'll make some money back on selling the 6.0 too, they are sought after for LS swaps.
LOL, yeah not many people pick up on that! It started out as my email well over 20 years ago, and was a natural fit for a forum username shortly thereafter. I've used it on every forum I've been on since.

Thanks for the heads up on the fuel pump assembly. This I had not seen (or noticed) when reading through swap threads.

Having dropped a 6.2 into my Tahoe you might want to consider the at least 60 cent a gallon difference between regular gas which runs fine in a 6.0 vs the required premium for the 6.2. There are plenty of threads in here about people trying to run less than premium in the 6.2.
Oh and I wish I had worked out keeping VVT.
The price at the pump is a stinger for sure. I've run premium in everything for years, with the exception of my beater Impala. My wife is the one that needs it drilled into her head!! Shouldn't be too hard to get her back on board though. The last 3 SUV's we had were premium required (or at least highly recommended).

You're non-VVT too with your swap? Interested in your thoughts on non verses keeping it as well!
 

PatDTN

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My '09 5.3 didn't include VVT. It and AFM were on the 6.2 I put in. Texas Speed had a deal on the LS9 cams and I included that with a kit to remove AFM. I definitely lost low end torque even compared to the 5.3!
 

Joseph Garcia

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Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving sage advice from the knowledgeable folks on this Forum.

To the experts on this Forum: Any issues with keeping the 4 speed transmission and mating it up to the 6.2 motor?
 

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