The 318 is a fantastic people move that can get good mileage.
To build a performance 318 beyond bolt on karts and a cam is not a route I’d take. Building a race engine 318 is something you have to want to do.
If there is a class where your cubic inch limited and/or there is an advantage to running a smaller displacement engine, there use can become viable. Remember the Trans Am Weiss where there was a CID limit of 5.0ltr.? A destroked 340 was the answer and the best way to go about it.
A member here, Austin Griggs holds a yearly event where you can compete with a 318 specifically.