Yah, I just posted that same question about a week ago. I ran GL-5 in mine and it did not mesh well (synchros) so I drained it and put ATF in its place and it shifts way better. Pennzoil Synchromesh and Mopar Synchromesh #4874465 were recommended as well.

http://i295.photobucket.com/albums/mm136/wings440/P8050125-1.jpg "Uhmmmm......I got nuthin'."