Hey all, this is my first post. I live in the beautiful Chicagoland, and I just got my hands on a red 1991 civic si for free. It runs pretty much fine (minus a few rattles and a sticky clutch). But I am really interested in tuning this puppy up and getting it to roar. As is, it have a performance air filter and muffler, but thats about it. My brother and dad know a lot about cars and can help me with the body work and getting it to look pretty. But the technical aspects are new to me. My main question to start is, what is the most reasonable engine upgrade for this chassis? It seems like most people try a DOHC like a B16A, but would more powerful B18C5 fit in? I sorta need help to start my search, so please respond.