To swap or not to swap.

I recently purchased a 1991 Nissan 240sx SE hatchback. I'm not the most knowledgable on cars but i'm starting. From what i read my model is the s13 and nissan used their 4cyl 2.4ltr DOHC truck engine in this thing. I hope to eventually race this car but what i wanna know is if this engine will cut or will i have to swap it for another. A lot of sites i go to say they've swapped the egine for the imported SR20DET but that thing would never pass e-check. So i'm lookin to put more power into my road car and most likely eventually race it. Is there much i can do w/ my current engine? and what are its limitations if any? I don't need all of these questions answered but any information that anyone can provide would be great! thanks.