Few months late to the party but thought this should be plugged here for anyone in need. I converted my drums to disc but the kit (Right Stuff) came with the wrong thread on the front anchor pin bolt for my 65 Impala. After searching everywhere, I did eventually cut off the end of the pin to make it a bolt; however, I stripped and subsequently had to cut off the other side. In the process, I needed another from ebay, junkyard, etc. All were expensive and hard to find.
I happen to have a friend that owns a CNC shop so I gave him a spare I had to reproduce it with the correct thread pitch. I'm ecstatic with the results. For a conversion, this is what you need. If you need the full original anchor pin with the spring portion as well, he's making that now (just gave him the original yesterday). If you can't find it, PM me and I'd be happy to connect you with him.