
Welcome to the Forum.
There are a lot of ways to get some more power out of your car. How much you can afford to spend, and what you want the car to be (something for everyday driving, or a "toy" for weekends, maybe), will affect your choices.
Many people start with the improved ignition system from a later model car (1978 Ford Fairmont). It can be bought as reconditioned parts, better than buying used pieces that often need service to start with. Many also choose to install a "performance" coil and spark plug wires.
After the ignition system is improved, next is often a bigger system of carburettor. Some choose to install a new carburettor with single venturi; like the old one but bigger. Others will buy a conversion set with a two-venturi carburettor, from a variety of choices. If you have money and dedication, there are kits to convert the cylinder head so it will use three carburettors; you may have seen pictures of this "Tri-Carb" set.
Your standard exhaust manifold can be replaced by headers. One problem for your situation will be high shipping costs, as these parts are large. With the headers, many people also fit dual exhaust pipes like on a V8.
These three stages of modification described above are probably the most common. There are more possible ways to improve the output of the engine, but they will also depend on the condition of your motor in the first place.
Finally, I will move this topic to the "Small Six Performance" section where more people may see it. You may even get replies en Español.
Regards, Adam.