Not many Corvair guys hang out here on the VCCA site. My son is a pretty saavy Corvair guy so I called him for some info.
MOST of the transmission related parts for your 1960 model are "one year only" parts. This does not necessarily mean that the parts will be hard to find. In many cases there are more parts available for 1960 Corvairs than there are cars to use them.
Your best bet is to go to Corvair center, (probably
www.corvaircenter.com) sign up so you can post, then ask your questions there. You will find those guys helpful and knowledgable. Good luck.
Mike