I am running Django, FastCGI, and Nginx. I am creating an api of sorts that where someone can send some data via XML which I will process and then return some status codes
Proxy timeouts are well, for proxies, not for FastCGI...
The directives that affect FastCGI timeouts are client_header_timeout, client_body_timeout and send_timeout.
Edit: Considering what's found on nginx wiki, the send_timeout directive is responsible for setting general timeout of response (which was bit misleading). For FastCGI there's fastcgi_read_timeout which is affecting the fastcgi process response timeout.
HTH.