The smoking issues with the 3.0 mitsubishi engines, were the center exhaust valve guide slipping out of the head and letting the seal slide off the top of the guide.. Pull the heads, pound the guide back into place, cut a small groove in the outside of the guide and slide a snap ring on it. Problem fixed.
The 3.3/3.8 engines are/were pretty much bullet proof. The transmissions in those those cars worked great after about a dozen factory fixes plus a special fluid designed just for those transmissions. It is called ATF+4 and is still the required fluid for most Chrysler stuff to this day.