L96-4L80E in 03 GMC

I am in need of some advice, wisdom, and encouragement please?

My project is a 2003 GMC 2500 and I am replacing the LQ4 with a new L96 and of course the newer ECU/TCM From what I have learned I can get a stock tune from a Chevy Express van that came with the L96 and 4L80E (which happens to be my tranny) what I am unclear on is what ECU/PCM/TCM/TCU would be the best to use with that combination, what years that was available and the simplest to tune. My LQ4 Gen 3 xx411 PCM but it manages the transmission and engine.

Should I get an E38 and T(42?) as separate or what is recommended? The donor vehicle is a 2019 Chevy 3500 truck and I have the complete wire harness but no ECU, VIN, TAC, or pedal. The harness has the two larger black and grey ECU connectors and the smaller blue one.

Any information would be greatly appreciated!

Putting an E38 in a truck that came with a P01/P59 is not something any sane person should ever attempt. Use the PCM original to the truck, and either change the crank reluctor to 24x & 1x cam sprocket (preferred), or use the Lingenfelter converter box if you're a weenie and don't want to open the engine.

Well I've called insane more than once but never a weenie. Thanks for the advice but if you don't mind what makes it so insane? I would think there would be some communication issues with the BCM and the cluster what else would I be up against?
I've read many of your posts on this site and the fact that you put it the way you did really makes me lean towards keeping the P59.
At any rate, thank you for the quick reply.

Because all of the modules in the truck are expecting to talk to and get info from a computer that speaks P59, not E38. You might as well try putting a Toyota ECU in it.

Most reliable way is to change the crank reluctor and cam sprocket. Ive never had any luck with the Lingenfelter converter boxes.
Then you dont have to waste all that money and time to try and figure out how to make everything work.
I just finished swapping a LS3 over to 24x/1x for a customer to put in a Fbody to run stock PCM. Its not hard to do at all. Machine shop i use dont even charge me to swap the reluctors now.

I've never had a bad LPE box. I'm sure it could happen but no problems here. Used a bunch of them

When you say the donor vehicle is a 2019----isn't that a DI engine you are putting into your '03? If so, your '59 is not going to fire the injectors.
I put a 2015 L83 in a 2000 Camaro and used a E38/T42, but I converted it to port injection.
None of the dash gauges work in the Camaro because they are all gone. Interior is stripped.

Gen 4 port injected L96 was used up through... 2021 I think? HD trucks and Express vans. Not everything post-2014 is DI.

Big thumbs up. Didn't know that.
I bought a Whipple that was for a 2019 Silverado from a buyer that was about to send it back. It was for a direct injected truck.
I called Whipple to see if I could swap the lower manifold for a port injected one and they told me that there was no 2019 port injected setups. Guess they meant---"They" didn't have one of those.
And, I guess there are not too many Express vans with blowers.

Quote:

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The L96 is essentially identical to its predecessor, the LY6. The primary difference is that the L96 is flex-fuel capable, while the LY6 is not.

Applications:

2010–2019 Chevrolet Silverado 2500HD/3500HD
2010–2019 GMC Sierra 2500HD/3500HD
2010–2013 Chevrolet Suburban 2500
2010–2013 GMC Yukon XL 2500
2016–2020 Chevrolet Suburban 3500HD
2010–2020 Chevrolet Express/GMC Savana 2500/3500/4500

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