Vin number on engine block

[blackdog76]

I bought an L86 and 8L90 for a swap project supposedly from a 2015 Silverado. It has no ECU, just the motor and trans so I’m trying to get a vin somewhere for programming reasons. I found what looks like a vin on the back of the engine block but it doesn’t come back to anything. The number is only 16 digits. Is there a missing number at the beginning?

[Z45]

[customboss]

GM  engine traceability label, is there a full decoder available here or does anyone have access to that for 2021/22 models? 

 

The TechLink upload above is not complete for each digit/letter nor defines terms. 

 

Thanks in advance for any assistance.