nvm some ass face took the info off...if ur only shooting for 300ish just go with a new oem bottom end(from nissan) have it balanced and get some good bearings.. the head doesnt need work just get a low miles head clean it up and slap that on...i made nearly 300 on a 150k miles ka and had no problems..and again the tune is the biggest thing if u wanna make reliable power...go on ka-t.org you'll find a lot of info that may come in handy..gl