For what its worth......
I bought a gold claw RS (prehistoric demon) from a friend, off of his 408 Windsor, and plunked it on my 406 Chevy. I don't think I even changed the jets, or had the bowls off. I thought it had the 850 sleeves, turned out to have 770cfm sleeves. Ran good enough in my car to get to 6.30s at Irwindale.
I have heard that there are many quality control complaints about the latest versions of the holley copy demons. I know nothing about the new thermoquad-like ones.
To be honest? I don't think it will improve any on your QFT.
