Need Urgent Help - ECU is from GMC Sierra 5.3 doesn't match LS2 engine.

[Wicked]

First off, forgive my ignorance. I have not worked with HPTuners in 3 years or so and have a urgent need
for help. After I post this, I will also hit the search but any help you can provide quickly would be appreciated.

I am trying to help a friend who need to get a car running basically yesterday.
He has swapped in a LS2 with Painless harness into a 1970 El Camino.
The ECU provided by the car's owner is the part number 12200411 called for by Painless.
I was able to read the ECU(junkyard ECU that the car's owner supplied) and the ECU has a VIN number for a
5.3 2001 GMC Sierra. We obviously need a vette or GTO tune to run the car.
The OS listed for the Sierra is 12202088. The 2005 GTO tune I found was a OS 12598977.

I seem to recall that if I tried to push a tune from a different OS, I will brick the ECU.

Please help me quickly.
Thanks,
Bradley Buchanan
PM me and I will provide my cell if u are available for phone assistance.

[Wicked]

Okay, after some research, it seems maybe I CAN "write entire" a different OS onto this 411 PCM. I've seen mixed information.
Does the new OS have to be valid for the 411 PCM AND the truck VIN on the existing PCM?

To recap.
Engine is a LS2 from a 2005 GTO. 4L80E is being used.
I have a 12200411 PCM
Current OS is 12202088 for a 2001 GMC Sierra 5.3
I need an OS for a 2002-2003 Z06 per Painless Harness instructions to go along with the 2003 Vette pedal and TAC module.
I also need the 4L80E segment swap. Can anyone tell em how to segment swap for the 4L80E?
And last but not least, how many credits would it take to do this?

Thanks,

[mowton]

Try this.....looks like it will work. Not that versed at segment swapping...perhaps someone else can chime in.

Ed M

PCM_Swap_Info_Rev_10.pdf

[Wicked]

Dude very helpful. Thanks.