We have a '94 Cutlass Supreme with 111,000 on it as a run-around town car (bought it with 30K on it)....- it has been pretty much trouble-free, except for GM's never-ending use of cheap interior parts and plastic everywhere. The hood release handle broke - there is a small vise-grip on the cable now to get the hood open....the glove box and hinges are falling apart.
We had to have the intake gaskets changed, they have been known to leak, and the injectors were just cleaned at 105K. It uses maybe a quart or so every 3000 miles, and has since we bought it. I have always used Castrol 10W40.
Other than that, it 's a pretty decent engine. The 3.4's are known to have more trouble than the 3.1's, especially the DOHC's.