I am with you on buying parts.
When you plug the maf in, does it blow black smoke out the tail pipes as it would when it went rich, or does it go the opposite way, no smoke and very lean?
You checked the Translator and saw ON, ON, ON, Off
The knobs are set for the correct maf 3" Lt1 or 3.5"
https://www.turbotweaksupport.com/files/translatorinstructions.pdf
I think you are down to talking to Bob...he designed it, and built it...but better, he worked in the GM research group and he understands as completely as anyone how these cars work. And, he is really a nice guy as well. I would try him bob@bailey-eng.com
Let us know what happens. I'm old but I still like to learn things LOL