04 Tahoe engine replacement, L33 or LQ4?

[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.