4.2 to 5.3 swap in 2WD 2004 TB

[Raydar]

From another thread...

If you wanna do a 5.3 swap, hit me up for how to run the PCM setup. Its a LOT easier than we all initially thought, remember the 03-04 LWB trucks came with 5.3s...run a 1MB LS1B PCM, flash the correct OS (a 5.3 TB OS), and do the wiring to match that of a LWB truck. Retain ALL creature comforts plus get a 5.3 (or whatever V8 you wanna throw at it, just adjust the PCM correctly. 4.8, 5.3, 6.0, 6.2, even a 7.0L ... [6.2, 7.0L need a converter box]).
...

This is exactly what I was thinking. A cursory look at the shop manuals seems to indicate that there are only a few wires that are different. I have Tunercat SW that allows programming, including changing the VIN in the PCM (which I am assuming will be required to allow the swapped V8 PCM to talk with the BCM and the rest of the modules.)

I presently also own a 2005 Silverado Crew with the 5.3, that actually uses less gas than my 4.2 TB.

I haven't hit Scarab up, yet, but I was wondering if anyone else had done this.
(This is not something that I'm afraid of. Just looking for potential "gotchas" that others may have experienced. I have done several swaps over the years. I presently have a Fiero with a Caddy V8 in it, mated to a Baretta 5 speed. Fools rush in... )

Thanks,

Steve

 

[ScarabEpic22]

Ha just happened to see this thread, and I'm quoted in it!

Right now I only know of 1 guy who has swapped a LSx V8 into his I6, Frank/checo has an 02 that he swapped all the wiring from a wrecked 06 TBSS in along with a lightly build LS7. I know another guy on here dropped a 350 and converted everything to manual, but lost the integration the factory PCM has.

You need a LS1B 1MB PCM+ correct calibration and a completely different wiring harness configured to match that of a 03-04 5.3. (i.e. you cannot reuse the factory I6 one without re-doing most of it.) You might have to flash the BCM as well with Tis2Web via Tech II or Mongoose cable.

 

[Raydar]

Hah! Cool. Thanks for the response.
I'm not sure what the PCM is that you mentioned. Of course, I have done essentially no research.
What I was picturing was using the entire engine, transmission, PCM and harness from a V8 TB EXT, moving the wiring in the body harness to match the V8 engine harness, and changing the VIN in the PCM to match my VIN. I figure that way, the PCM and BCM will both be happy.
I don't know if there are any constraints within the architecture that prohibit changing the VIN to something different. I especially don't know if anything is keyed off of the 8th digit, in regards to what engine the PCM will look for. (I seriously doubt that, but I've learned not to count on anything.) I DO know that that the OBDII Tunercat program that I have, will allow you to change the VIN in the PCM. At least the guy who writes the code told me that it will. (At one time I was contemplating an LS swap into a Sonoma that I used to have. It was a question I asked.)
If I decide to do this, I'll document it here on the forum.