That was my guess based upon the casting shape.The aluminum intake with the Holley carbs started life as a factory 409 dual quad intake.
I see three bellcranks. Holly two barrel's.The Walden 3x2 looks like 3 air cleaners setting on a pair of Holley 4 barrels
BeautifulSome day I will do a thread on the attached, which started when Tom K posted a picture of some "garage art". All I can say is I learned more than I wanted to about Holley/Ford 94 carbs, and that I am not done yet...View attachment 68707
Did you try a 340hp small port 409 intake?