I noticed there hasn't been any talk here or on EFI Live's web site on the Vortec PCM. Apparently there is a option to read/program this older PCM with the latest update. I successfully read a 1999 C1500 5.7 PCM only to be stuck with an error message. I was unsuccessful trying to read a 1996 PCM.
Unrecognised PCM "This version of the EFILive Tuning Tool has not been configured to display this PCM's operating system."
Does anyone have any additional information for this PCM? I have tried other files, it will only attempt to load files that are 512kb or 1 or 2 meg. The early Vortec files are only 256kb.