Torque to yield, head bolts...

When those ran they ran well. I drove a demo Century on a couple vacation trips. 35 mpg but they only had TH125 trannys I believe. Not a beefy transmission for a diesel. When GM came out with the 6.2 and then the 6.5, the 700 R4's just came out. Of course they put them behind a turbo 6.5 in a 4 wheel drive. The salesmen would sell them to a farmer that would use it like a grain truck, pulling big wagons of shelled corn in overdrive. Glad I don't work there any more.
I was given an 80 sedan deville that started life as a conversion diesel , 65k warranty swap , 135k (60k new ) warranty swap , GM and the dealer teamed up and made the original owner take an olds 350ho gas motor instead of another diesel . I got it with 195k on it and sold it with 335k .Car had a metric th250 trans that had finally given up and nobody in the Lansing area wanted to touch it due to lack of local parts .But the motor still ran like a champ .