04 Tahoe engine replacement, L33 or LQ4?

[mattt]

Let's hear opinions, past experiences -BTDT, or other information on engine replacement for a high mileage Tahoe, Suburban, or Yukon with a standard 5.3 LM7/L59

L33 = 5.3HO (all aluminum) from 05-07 1500 4wd truck
LQ4 - 6.0std from Denali, 2500HD etc

 

[OR VietVet]

I would always reach out to Jasper Engines. I have used them many times over the years with no problems. Any engines they rebuild always get top quality components and if there are any recall or TSB improvements that are needed, they do it.

 

[iamdub]

Either one would be an upgrade on some level. Out of those two, the L33 would likely be the most expensive since it's not as common and an aluminum block. It's power gain over the LM7 would be minimal as well. Since it's more common than the L33, the LQ4 would likely be cheaper. It would also be the better dollar-per-power gain since it'll have more HP and TQ than the L33.

 

[Mechanic421]

Hard decision i have a lq4 and love it. But weightlose is always good thing in trucks.

 

[Wylie_Tahoe]

9 out of 10 times, displacement wins. However, I do not know enough about the L33's performance to compare it to the 6.0.

 

[Rocket Man]

I know my LQ4 is an awesome engine. I have no experience with the L33 although I think any weight savings won’t matter much in a heavy SUV.

 

[rockola1971]

Honestly I need to know more about where you are going to source your engine and what your goals ultimately are as far as intentions with the vehicle. Im assuming you would be getting a used instead of reman L33 since you listed the specific year and model engine would come from. Finding a 2004-07 engine with low enough mileage to even mess with is going to be hard and will only get harder as each week passes. Putting in a 6.0L when vehicle was originally equipped with a 5.3L (Im assuming) can get pretty expensive with all the items that will need changed out for compatibility.

Honestly if it were me and you intend on keeping the vehicle for some time I would just get whatever came factory in the suv and get a reman engine to stick in there and easily doable over a weekend.

 

[Rocket Man]

Honestly I need to know more about where you are going to source your engine and what your goals ultimately are as far as intentions with the vehicle. Im assuming you would be getting a used instead of reman L33 since you listed the specific year and model engine would come from. Finding a 2004-07 engine with low enough mileage to even mess with is going to be hard and will only get harder as each week passes. Putting in a 6.0L when vehicle was originally equipped with a 5.3L (Im assuming) can get pretty expensive with all the items that will need changed out for compatibility.

Honestly if it were me and you intend on keeping the vehicle for some time I would just get whatever came factory in the suv and get a reman engine to stick in there and easily doable over a weekend.

Pretty much everything from the 5.3 can go right on the 6.0 excluding the ECM. It’s a fairly easy swap.

 

[mattt]

Thanks for all the opinions and experiences here. I lean towards the 6.0 but have located an affordable L33 5.3ho. I know there is no replacement for displacement.


There are things about the 5.3 that have appeal. It's flat top piston, good heads, unique cam make it an interesting bird to say the least. Is there anyone out here that has swapped in an L33 already?

Thanks.

 

[rockola1971]

Pretty much everything from the 5.3 can go right on the 6.0 excluding the ECM. It’s a fairly easy swap.

MAF, Radiator, Engine wiring harness and pinout, torque converter, starter all the same?

 

[Tonyrodz]

MAF, Radiator, Engine wiring harness and pinout, torque converter, starter all the same?

Yes. I went from 4.8 to 6.0. Everything is the same--except the ecm tune.

 

[Rocket Man]

Yes. I went from 4.8 to 6.0. Everything is the same--except the ecm tune.

Oh yeah, I forgot even the ECM is the same, just need a tune. Thanks Tony.

 

[Taavi]

I assume there would be no difference, if LQ4 or LQ9 goes in to replace LM7, am I right? But can the gearbox from LM7 handle the added torque?

 

[swathdiver]

Let's hear opinions, past experiences -BTDT, or other information on engine replacement for a high mileage Tahoe, Suburban, or Yukon with a standard 5.3 LM7/L59

L33 = 5.3HO (all aluminum) from 05-07 1500 4wd truck
LQ4 - 6.0std from Denali, 2500HD etc

The L33 was the precursor to the Gen IV 5.3s. It's basically a Gen IV LC9 without AFM. It has a single pattern camshaft, 243 heads, flat top pistons, 9.95:1 CR, makes 310 HP and 335 TQ. It's not a FlexFuel motor though.

FYI: When fellas are deleting AFM in their 5.3s, the camshaft from the L33 is the one they should be using if wanting the same stock grind numbers. VVT engines are dual pattern, so this applies to 2007-2009 LMG, LC9 and LY5. If the 2010-2014 engines delete VVT, they can use this stock cam too. VVT is good for about 1 mpg though, so consider that.

The block is 80 pounds lighter than an iron block.

https://help.summitracing.com/app/answers/detail/a_id/4823/~/chevy-l33-engine-specs

https://help.summitracing.com/app/answers/detail/a_id/4809

Pay attention to the year of the LQ4, the early ones had iron heads. At best the LQ4 makes 20 more horsepower but makes at least 25 FTLBS more torque.

 

[mattt]

The L33 was the precursor to the Gen IV 5.3s. It's basically a Gen IV LC9 without AFM. It has a single pattern camshaft, 243 heads, flat top pistons, 9.95:1 CR, makes 310 HP and 335 TQ. It's not a FlexFuel motor though.

FYI: When fellas are deleting AFM in their 5.3s, the camshaft from the L33 is the one they should be using if wanting the same stock grind numbers. VVT engines are dual pattern, so this applies to 2007-2009 LMG, LC9 and LY5. If the 2010-2014 engines delete VVT, they can use this stock cam too. VVT is good for about 1 mpg though, so consider that.

The block is 80 pounds lighter than an iron block.

https://help.summitracing.com/app/answers/detail/a_id/4823/~/chevy-l33-engine-specs

https://help.summitracing.com/app/answers/detail/a_id/4809

Pay attention to the year of the LQ4, the early ones had iron heads. At best the LQ4 makes 20 more horsepower but makes at least 25 FTLBS more torque.

And one more footnote to mention is that the early LQ4 with iron heads has a different crank with spacing that will prevent it from bolting up to a 4L60/65 transmission. It is only usable with a 4L80 or similar transmission from what I've been told.

 

[iamdub]

And one more footnote to mention is that the early LQ4 with iron heads has a different crank with spacing that will prevent it from bolting up to a 4L60/65 transmission. It is only usable with a 4L80 or similar transmission from what I've been told.

You're speaking of the difference because that earlier design was mated to the earlier style 4L? GM made a spacer ring for that (part number 12563532). You use that spacer and a flat flex plate.

I'd avoid the iron head LQ4 anyway.

 

[iamdub]

I assume there would be no difference, if LQ4 or LQ9 goes in to replace LM7, am I right? But can the gearbox from LM7 handle the added torque?

No physical fitment difference. The gearbox will handle it for a little while, but it's more dependent on how well you can control your right foot.

 

[mattt]

You're speaking of the difference because that earlier design was mated to the earlier style 4L? GM made a spacer ring for that (part number 12563532). You use that spacer and a flat flex plate.

I'd avoid the iron head LQ4 anyway.

From what I've been told, it's my understanding that the crank is around 3/8"-1/2" too long to work with the smaller/lighter duty 4L60. Since that engine only came in front of a 4L80, that is the only trans it works with. A spacer can't help with too long, only too short. I've spoken to a machine shop and they indicated it's not worth the machine time to shorten the crank snout. They suggested swapping to a later crank and putting it in the old 1999-2000 block to make the change.

 

[mattt]

I assume there would be no difference, if LQ4 or LQ9 goes in to replace LM7, am I right? But can the gearbox from LM7 handle the added torque?

It will bolt up, but GM found it necessary to upgrade the standard 4L60 and call it a 4L65 which is what you find in Denali Yukons and Escalades. The 4L60 & 4L65 are built from the same transmission case. I believe it to be a 5 gear planetary gear in the 65 vs. a 4 gear planetary in the 4L60. If/when dropping a 6.0 into a vehicle it didn't come in, I would see the value in upgrading your trans to a 4L65.

 

[iamdub]

From what I've been told, it's my understanding that the crank is around 3/8"-1/2" too long to work with the smaller/lighter duty 4L60. Since that engine only came in front of a 4L80, that is the only trans it works with. A spacer can't help with too long, only too short. I've spoken to a machine shop and they indicated it's not worth the machine time to shorten the crank snout. They suggested swapping to a later crank and putting it in the old 1999-2000 block to make the change.

Ah. I kinda recall those details now. It's been a few years since I bothered looking into all that. You're much better off getting a later LQ4, anyway.