GM engineer told me that the early T1 trucks (19 to 22 classic) were actually a modified K2 platform truck and that the electronic issues are gone on the 22 and up T1 trucks. These are the trucks that have super cruise on some high end models. He also told me to except to see displacement on demand on the 3.0l diesel in the next year or two (along with higher torque/horse power numbers).

Jay