2007 4.3L V6 swap - learning curve help please!

[dgiller]

I'm swapping a 4.3L V6 from a 2007 Silverado Classic (Gen III) into an old Volvo C303 military vehicle. The mechanical work is all done. I'm trying to sort the EFI, and I could use a little help. I'm a quick study but I'm new to EFI tuning. I have background in microcontroller programming and electronics so I understand the theory but am having to learn everything about these GM EFI systems.

I bought a PCM with the donor engine. It was advertised as being the PCM from the donor truck, but it isn't... not even close. It's from a 2003 S10 auto. I've also got another 2003 S10 PCM, this one manual. I had a bad engine harness and chopped it to make a bench harness for the PCMs.

I bought a FlashScan V2 and have read both of the PCMs (but not flashed them, so I haven't used any licenses yet).

Other pertinent info: drivetrain is assembled from a SM465, Ranger OD, and a Dana 18.

The two PCMs I have are:

Manual
Hardware 12570558 (per label)
OS 12579405

Auto (4L60E)
Hardware 12575502 (per label)
OS 12579405

I'm not certain I am identifying the hardware number for the PCM correctly.

My initial questions:

1. Does anyone know the LU3's well enough to tell me that the 2003 PCM/OS will work fine with my 2007 engine and engine harness? Should I just start with the PCM that's already configured for manual transmission and run with it? The 2003 harness was so different from the 2007 that that makes me nervous. The MAF is different too, as the 2007 apparently has IAT built in and the '03 doesn't (I have an '03 MAF that won't work with the '07 harness, and I don't know where the IAT goes on the '03 engine).

2. I'm expecting the answer to #1 is that I shouldn't try it. I'm wanting to get this thing running, and I'm not excited about buying a third PCM. I've shopped around and the closest I've found is an '06 Express Van PCM. The guy looking up the PCMs for me said the hardware part number is coming back the same all the way back to 2003 (didn't see the listings myself though).

These are 1mb PCMs as I am pretty sure the 2007 is. Can anyone tell me if I can flash a 2007 OS onto one of these two PCMs? Are all 1mb PCMs interchangeable (in terms of hardware)?

If so, can someone give me a stock tune/OS for a 2007 V6 Silverado Classic? (2006 is probably fine, as 2007 "classic" was just a carryover from the 2006 while they introduced the new E38-based trucks)

I looked at HoldenCrazy's repository and didn't find any 4.3's later than 2004.


General suggestions on the least painful way to get a baseline running truck that I can learn to refine the tune on later would be helpful too.

Thanks,
Dave