Running the tubes as shown would keep the carb from freezing in cool damp weather but would not do much for cold engine fuel evaporation.

Have a look at a carburetor V6 or V8 engine, there is an exhaust cross over passage from head to head under the floor of the intake manifold, this is where you need to direct heat. ( when I said "bottom of carb area" I should have been more clear with " floor of intake manifold". )

Also have a look at a air cooled VW intake, they have the steel exhaust tube / steel intake tube cast together with aluminum.. There isn't enough heat there to catch things on fire however, if you run an exhaust tube you may need to insulate it so things around it don't catch fire.

Does this engine use an EGR valve? That would be a good source for an exhaust supply. Does this car use an AIR pump? That could be a good place to return the exhaust.

If you are in a warmish climate, you might get away with a heat stove on an exhaust manifold, flapper valve and vacuum thermostat. Look at any car from the early 70's for a diagram of a heated air intake system. This coupled with hot water under the floor of the intake manifold might be enough.

All of this will take some experimentation.