Current Setup:
2004 GTO, Automatic 4L60E, Procharger
GM LS1B: Service 12586243, HW 12583659
OS: EFI Live Custom 04110003 upgraded from stock 12587604 (flex fuel disabled)

I have googled a lot of the different and followed the install on https://ls1tech.com/forums/pcm-diagn...-write-up.html.
I suspect that I need a different base OS but wanted to verify before going down that conversion.

(1) Would my current setup be capable of a flex fuel sensor?
OR
(2) Find an equivalent custom EFI Live OS tune - Example: an automatic trans version of https://forum.efilive.com/showthread...l=1#post237782.
OR
(3) Would I have to flash a stock tune that had flex fuel enabled? Example: 2004 Tahoe, L59 5.3L, PCM 12587603, and then upgrade to EFI Live Custom 04073003.