CE short block was totally new. If a warranteed block was *rebuildable*, then the rebuild was done at the dealership, but usually it was *cheaper* for GM to just provide a replacement short block, although I suspect if an owner screamed that he didn't want a replacement block and that the original was rebuildable, then that might have made a difference...
Warranty at the time was 5/50 (5 yrs or 50K miles) on the drivetrain major components.