hey, i have an old continental mower, identical to the mustang mower. if that helps. i cant find any information on this mower at all. i am not worried about history, i just want to get more speed out of it. the gear box only has forward, neutral and reverse. it has an 8hp Briggs and Stratton motor. i dont need it to do 40 mph. but maybe 20 to 25 mph. i read something about changing the pulley's but i dont know exactly what they were talking about. the shaft is vertical, if that helps any. please respond if you could give me any advice. thanks for the help.