The 3.0 litre is an excellent engine but will burn oil over time because Chrysler didn't want to put the "good" valve seals in that Mitsubishi offered so it ultimately led to its demise and was hated by many. If you kept the oil topped up or replace the valve seals with ones available from a Mitsu dealer the engines were bullet proof and lasted forever.
There was also a couple of years where Chrysler chose not to use an EGR valve with this engine and it sent the NOX through the roof and many of these non-equipped engines would fail emission tests, blow head gaskets, crack heads, create oily sludge goop in the engine and deteriorate seals like crazy because the heat in the engine was too intense due to high cylinder temperatures.
They also had some early engines that would drop valve seats because of this heat problem and because Chrysler was too cheap to take Mitsu's advise and put a special clip in that would prevent it from falling. They were later forced to because of too many incidents.
My dad has one of these old ones (with an EGR) and it has almost 400K KM on it and runs great. But it burns a bit of oil... (So what)
The 3.3 never had any of these problems and although used outdated pushrod technology never had any issues lasting many miles untouched and without consuming the oil the 3.0 litres did.
The transmission for either was junk and is still junk, but got much better over the years.
For a budget mini-van it lasts long enough with proper care...