Carb question - Holley street demon?

[asickber]

I have been having some issues with the Qjet on my 402BB. I had a mechanic I know that is familiar with the older carbs tell me it's probably too far gone to be worth rebuilding. Was planning on going a different route but found a Holley Street Demon 650 basically new for a good price. Would it be worth looking into? Would I need to make any modifications to run this on my 72 Longhorn or would it even work?
I'm not too familiar with carbs in general.