I have a 2007 town and country with a 3.3 v6. I got transfer gears from a 3.8 in the junk yard. I will swap them, the 47/49 to 50/46. Overall top gear ratio will be from 2.49 to 2.2. Will shift to OD at 51 mph, now shifts at 45 mph. Will be 1800 rpm at 65 mph, now at 2050 rpm, hwy mpg should increase from 25 to 26.5.
...Taken from the ATSG Chrysler A604(41TE) Update Handbook (1999)