Hoping I can still use the Twitter API to perform thousands of requests: [Wayback/Archive] Burninator Sec: Twitter Removed the Blocked Account Export – Let’s Put it Back!
I dug around in the Data Archive and eventually found block.js, which is a JSON object of all the blocked accounts in their ideas. From there you can write a quick Python script to use the Twitter API to resolve all of those IDs to usernames.
Related: [Wayback/Archive] How to download your Twitter archive and Tweets | Twitter Help.
Via [Wayback/Archive] twitter export blocklist – Google Search and
The Wiert Corner - irregular stream of stuff 