The engine I'm rebuilding (Skoda Estelle '72, RWD, rear mounted engine) is the same from previous models, with slight different changes. One of the things they modified was the intake manifold which, as I'm guessing, correspond to a different carburetor being provided. I have the two kinds of those manifolds, but the carburetor I'm adapting comes from a classic Lada. The Lada manifold has one single slot in the carburetor seat; the manifold that came with the engine is the kind with two interconnecting "holes":
The first top pictures is the manifold that came with the engine, the picture below is the other manifold resembling very much a Lada's (from which I will use the carburetor).
My guess is that in the "holes" manifold, the top hole which has an insert ring, provides something like a pool of gas, to help the engine crank perhaps in cold Czech winters :) When I teared the engine into parts, I could see a puddle of gas there. To start this engine (which already had a Lada carburetor) I had always to kick the gas pedal a few times before running the starter.
The second manifold does not comes with the vacuum port for the brakes, but that's something I can add.
So my question is a bit complex, hopefully someone with experience could guide me:
Is there any real benefit or not (from any angle: consumption, performance, etc) by installing the second manifold? Besides just resembling the Lada's carburetor seat...
Pics of the Lada Carb against the second manifold