318 or 360, 727 or 904

I wouldn't do an adapter. If you want to run the 2 bbl as the 360s did simply swap to a 360 intake. I've do e that before on an otherwise stone stock 318. Problem is that particular Holley is "feast or famine"... If you get a good one it's really good, otherwise they're crap. I've rebuilt my share of those carbs, not hard at all.
Skip the adapter if for no other reason than being so much easier to deal with the trans kickdown linkage, with an adapter you raise the carb which puts everything out of sorts and creates problem of it's own. That and trying to choke the mixture from a bigger carb they a smaller plenum doesn't give as good of results either than being directly bolted to a manifold flange that's sized for it