Sierra 2007 (new body), 5.3L swap to 2003 6.0 LQ9?

[Sergio Mendez]

Hi, new to the forums!

 

My dad has owned a sierra 2007 for a long time now. It currently is around 350k miles with a rebuilt 5.3L around 120k miles. Transmission has never been rebuilt nor repaired.

 

Car has been well maintained overall, but the engine feels weak and tired now.

 

I'm in need of a towing truck for my toy hauler, and have been toying with the idea of swapping the 5.3 for a 6.0 LQ9 from a 2003 Chevy 1500, since all new/used trucks are crazy expensive due to the pandemic.

 

A jump to the 6.0 would also  give me some increased towing power also.

 

I found an LQ4 with 130k miles, pulled from a sierra 2003 1500. It comes with 480L tranny, ECU and harness.

 

I feel like this should be a direct swap, but is there anything else I should know?

 

Would this still be a reliable car after an engine swap? Don't want to be left stranded on the road with a 21' toy hauler In Baja .

 

Edited August 2, 2021 by Sergio Mendez

[CamGTP]

It's not a direct swap. Those are two different engine generations.

 

The LQ9 is a GEN engine that is a 24/1x crank/cam trigger and the 2007+ 5.3 that you have is a 58/4x trigger. They do not swap over. The knock sensors and the cam position sensor are also in completely different spots between the two engines.

 

Your best options are to find a L76 6.0 from a Vortec Max truck or a 6.0 from a 2500/3500 truck that is also 2007+. The most common is the LY6 or L96 engine. Obviously you'd need to tune the computer for either swap.

Edited August 2, 2021 by CamGTP

[Sharpz]

why not just overhaul your 5.3?  If it is a good block it wouldnt take much.  Aside from either size engine, it sounds like you are in the market for a tranny more then a motor. 

[Sergio Mendez]

2 hours ago, CamGTP said:

It's not a direct swap. Those are two different engine generations.

 

The LQ9 is a GEN engine that is a 24/1x crank/cam trigger and the 2007+ 5.3 that you have is a 58/4x trigger. They do not swap over. The knock sensors and the cam position sensor are also in completely different spots between the two engines.

 

Your best options are to find a L76 6.0 from a Vortec Max truck or a 6.0 from a 2500/3500 truck that is also 2007+. The most common is the LY6 or L96 engine. Obviously you'd need to tune the computer for either swap.

 

Thank you!

 

I see a LY6 available near me, might go take a look. Will do some more research from people that did a similar swap.

 

 

[Sergio Mendez]

18 hours ago, Sharpz said:

why not just overhaul your 5.3?  If it is a good block it wouldnt take much.  Aside from either size engine, it sounds like you are in the market for a tranny more then a motor. 

 

It was rebuilt at around 120K miles... Not sure how much power can be squeezed from a 5.3

 

Toyhauler has a GVWR of 7500 lbs. Im estimating that with ATVs and toys loaded, I'll be around 8500lbs . That would be over the recommended towing for the 5.3 by quite a bit, and borderline for the 6.0

 

I know the ideal thing would be to just buy a bigger truck, but with current prices and inventory, thats not an option.