First, of course, it has to be a small base. (Later cars have the larger version.) You also want to find a Chevrolet carb with the fuel inlet on the side; they are much easier to deal with than one with a front fuel inlet. When mounted on the manifold backwards, the fuel line and throttle linkage almost fall into place.
The problem comes with the manual choke, as it pulls backwards. You can rig up some sort of "monkey-motion" linkage, but what I have done is use an automatic choke version. Mercury's had automatic chokes in two versions, "divorced", where the choke actuating mechanism is mounted on the manifold, and "conventional", where it is mounted on the carburetor. Luckily, 2G's also came in both versions, and I have been able to match them up. A "divorced" mechanism just needs the actuating rod from the mechanism bent slightly, while the "conventional" setup needs the tube from the manifold shortened. I have done it both ways and either works fine. The problem is going to be finding all the parts you need, as people have usually stripped the Merc manifolds and small base 2G's of any kind are getting harder to find. I found a place that was selling Chevrolet small base cores for $49.95 and $79.95, depending on configuration.
The carburetors don't mind running backwards a bit, and I'm sure you'll find a properly set up system to be very satisfactory. I don't miss the manual choke at all.
"Ask me what time it is, and I'll tell you how to build a watch".
EDIT : Here are the guys with the cores :
https://hotrodcarbs.com/store/small-base-rochester-2gc-2gv-carburetor-cores.html.