My 86 Tecate-3/86 KX500 project is complete except for lengthening the swingarm. The project and all free time was put off due to getting married and kids. The crank HAS to be balanced or the Tecate-4 will shake itself apart and possibly break the frame. Balancing the crank will shift the engine vibration to a RPM that you rarely constantly run at. Dave Roberts at ILR Performance is a Tecate guru and knows about such conversions. I don't have is info. handy, but a bit of surfing should help you contact him. The motor will bolt right in with minimal mods (front and top mounts mainly).
Good Luck!