I have mentioned many times in these forums my dislike for Edlebrock carburetors. I’ve tried them on many engines (I’m a slow learner) over the past 20 years or so. Rarely with good results. I currently have two sitting on shelves in my tool room along with 3 quadrajets. I’d rebuild the quads before using one of the clones. The aluminum adapters are less than $50 and will adapt Edlebrock or Holly to your 409. Have fun with it.
🛠

Martin
'62 Chevy C-10 Stepside Shortbed (Restomod in progress)
'47 Chevy 3100 5 Window (long term project)
‘65 Chevy Biscayne (Emily)
‘39 Dodge Business Coupe (Clarence)
“I fought the law and the law won" now I are a retired one!
Support those brave men/women who stand the "Thin Blue Line"! Hug a cop!
USAF 1965-1969 Weather Observation Tech (I got paid to look at the clouds)