Here are the GM part numbers for all 4 oil cooler lines:
Pipe, oil cooler inlet, the upper alum pipe,.......14061344
Pipe, oil cooler outlet, the lower pipe...............14061345
Hose, oil cooler inlet,.....................................14061346 exc. ambulance which is......14063336
Hose,oil cooler, outlet....................................14061347 exc. ambulance which is........14063337
I know the lower pipe is available, I just bought one at my Chevy dealer for about $38
Merry Christmas to all, JT