Since LX cars have their radiator cap on their goofy shaped coolant bottle, this $12 filler neck from Dorman(902-305) and made for a 00-04 Durango should work. I'll double check the ID of the my upper hose before ordering.
Those things can get very brittle and crack. Jegs makes an aluminum version for about $15 more.
After my mom's 3.9 Dakota scalded the crap out of me, I replaced hers and the one on my 2000 Dakota R/T.
I like this swap Idea. We rented a '14 T&C for a trip through the mountains of North Carolina (several times, actually).
One one occasion we had 9 people and luggage for three of them stuffed in there, and were traipsing about in the back country up and down steep switchback gravel roads.
That 3.6 didn't even break a sweat. I've been a big fan of that motor ever since.
