Hey, I have a 91 Civic hatch Si wih like 190,000 miles on it. The engine is still pretty strong but let's face it, this bitch doesn't have any more good horsepower and I don't think it's necessary to upgrade it. My question is, should I rebuild this engine and just build it up slowly, should I buy a ZC engine even though I hear they have problems, should I buy a B16A, or should I buy something else? Also, Rebuilding the engine sounds like a good idea because I could find parts easily such as and exhaust without it having to be custom built. I have no clue where to get any ZC engine parts so links would help if you could. Also, the b16A would be affordable but then I would have trouble with upgrades and stuff because of the price which is about $1800. Also, if I get the ZC or if I rebuild my old engine, is there a way to get a 5 speed tranny? I really don't like 4 speeds. I used to drive my dads truck which was a 5 speed and I always have a tendency to shift into 5th on my car which sometimes leads to shit. Thanks for the help, I really appreciate it.