i use just about any 15-40 that is on sale in the 5 gallon bucket in my 99 caravan with 170k on the clock.
same goes with the ATF in the transaxle i installed, semi-rebuilding it and installing a TransGo shift kit.
my bus has the 3.3 engine, but i don't know if there are any similarities between it and the 3.6 engine, [being in the middle] or the 3.8 engine.
or does the 3.6 engine have more things in common with the newer, larger [4.0 ?] v6 ?