I found a '04 C1500 5.3L os12587603_test1.bin and a OS matching XDF file Operating System 12587603 - 1Mb PCM - 2004 model year. loaded into tunerpro rt and Disabled VATs. Still getting an error...

Just getting started on the LS Droid, doing a junkyard 4.8, 4l60e swap. The PCM I have is displaying OS 12579405. I have tried a couple different XDFs but I keep getting an error when trying to...