There's quite a few around here, particularly under the Blogs tab. Outside of the forum, there's a couple on Gay Spiral Stories. Willie Cici and Rozza22365 usually wrap them into their stories. There's also Male Body Exchange (http://malebodyexchange.blogspot.com) run by our forum's own Muscledrain and the Male Transformation Blog (https://maletransformation.blogspot.com). Both have links to other sites, though some are likely dead after Tumblr decided to do the Thanos Snap. There's also "Becoming..." but I can't for the life of me remember the link.