Saw a link to this source on another site. They have a bunch of miscellaneous trans related parts for our cars that can sometimes be hard to find. The prices don't look bad.
http://neperformancemustang.com/catalog/product_info.php?cPath=65&products_id=74
http://neperformancemustang.com/catalog/product_info.php?cPath=65&products_id=74