HRM offers several different styles depending on which one you are interested in. They are part of a trans-kit but I assume he would sell the hardtop separately.
LeMan Hardtop:
Small Window:
Large Window:
Kurt here are a few pictures I found of what I believe is a similar intake manifold, they do appear to be relief valves of some sort. Not sure about the blower size, maybe someone else could chime in?
Great solution and executions. I found these photos after a search for Ford 427 Supercharger.
https://www.jalopyjournal.com/forum/threads/mickey-thompson-427-fe-blower-intake.1020108/