Selecting the right mask

[Paraquat]

Hi everyone.

I have a 6.0 waiting to swap but I'm trying to take some time and understand what's going on in my current 5.3

I bought it used, unknown everything. Replaced every gasket except the head gasket, rewired the harness, paid to have my ECU flashed, and sent it. I requested the flasher flash it for 3.42 rear diff, but I went with a 4.10 rear end instead.
I figured I could change my own rear end ratio.

I have a 09354896 ECU. It ias a red/blue. When I bought it, it was supposed to be a drive by cable 5.3 and it came with a flex plate on it, so automatic. Searching the forum said to use the 12212156 mask.
When I use this mask I came up with a type 17 engine with 154 cylinders. I am hesitant to start altering pulses and values if I don't have the appropriate mask (see, I read the tutorial)

So I used this mask to extract the VIN number and trace the vehicle back to a 2001 Silverado 1500.
Ok, search for 2001 masks. I found a 2001 mask but when I try to open that mask I get an error:

Failed to load D:\bin files\12202088 - 2001 512k.xdf
Unrecognized encoding (parser does not support UTF-8 language encodings)

Same with another 2001 mask I downloaded, called 12208322.

I found another mask called XDF for Operating System 12208322 - 2001 512Kb PCM - Version 5.xdf but this one also says I have a type 17 engine, with 154 cylinders.

Half of me wants to know what's going on and half of me wants to just scrap it until the 6.0 with the 0411 goes in. Someone named Woody uploaded a 2002 2500 4x4 6.0 NV4500 which is the exact file I needed. It should be as easy as confirming that rear end ratio and running it, but I have a TBSS manifold and 36 lb injectors I want to put in.

Does anyone have any input?