They had gotten rid of the V6 diesel by 1981, and then they used the infamous 350 diesel
https://www.curbsideclassic.com/automotive-histories/automot...
https://www.curbsideclassic.com/automotive-histories/automot...
“The 4.3 L V6 that came out in 1982 did have a denser head bolt arrangement, and did not suffer the catastrophic head sealing failures of the V8.”
V6 diesels were put in Cutlass’ until at least 1984:
A friend of mine had one as his high school car, but his dad converted it to gasoline. I think it was in an Olds 88