Have you looked at the engine number. The 3 bolt manifold was only offered on 302 engines. The three bolt will fit the 1952 270 engine that had the big port head, but the 270 engine was not offered with a 3 bolt carburetor. Your engine may very well be a 302 someone transplanted into it. Are you sure that it is actually a Holley 94. A Holly 94 had port vacuum which worked with the Ford Load A Matic distributors. However the 94 can be converted to run with manifold vacuum.
The carburetor on the right is a Ford Holley. The two on the left are GMC Holley
https://photos.app.goo.gl/huYaXYVgMown5nwR9It really wouldn't surprise me if that isn't a 302 engine. Well, I now see in your last that it is indeed a 302. Anyway, take a look at the photos. I really doubt that you have a Ford Holley.
