Here are some links that may help you out the first one has the ATSG manual listed for download and the second has the detent repair kit listed part way done the page.
http://www.mymopar.com/index.php?pid=22
http://www.transmissioncenter.net/727transmission.htm

Good Luck

Living with ALS help support the search for a cure
Thanks http://web.alsa.org/site/TR/Walks/WesternPennsylvania?team_id=347781&pg=team&fr_id=12069