How DARE you bring anything to this discussion except complete agreement!! NOT! lol
I have a 650 Holley spreadbore in FL, but I never had a chance to use it. All I can say w/complete certainty is: That has got to be the heaviest carburetor in existence! First time I lifted it, I thought it was nailed to the floor!!
Someone who is knowledgeable here uses or has used one, and IIRC had good things to say about them, as well. Might have been a mod, just can't recall for sure.
But in any event, it certainly would be an option- as long a 800 CFM was chosen, I think a 650 wouldn't be quite enough.