I don't think you can "crawl a site" to find links that are not live. Crawling a site means you follow the links on the site that are live from one page to another, hence the term crawling.
The only way I can think of to do this is to find a site that allows for directory listings (no default index.html/php) and find the links there. You see, if nothing links to a page you either have to know the page is there or get it via a directory listing.
However, that being said I don't know how Google finds some of my webpages. I purposely don't link to some webpages but they still end up indexed. Maybe someone else knows a trick I don't. Good luck mate.