Purchased the van from a friend. The brake system had failed, a/c quit, shocks were toast, and transmission shifted into 1st without warning, scary. Brake system was recalled, but still paid a pretty penny, a/c and shocks fixed myself, and the tranny is still the original. The 3.3 liter tranny will drop down into 1st if: the solenoid pack, tranny computer, or even the throttle position sensor are malfunctioning. I replaced all myself, and it works fine. I did take it to a tranny man, and he said from a computer diagnosis, the tranny looks in great shape. Only reservation I have about it, is it has a little hesitation going up steep hills at high speeds (e.g. 70 m.p.h or above.
Captain chairs upfront, bench in rear, and lots of room. Fairly dependable. Even though I am not a computer in cars fan (and this van is loaded with them, tranny comp, engine, abs comp, etc) It is pretty neat what they can tell you.
A bigger, stronger tranny to handle the weight of the van, and maybe slightly stronger engine to handle the weight. Of course, increase gas mileage.