well the LC´s vary in top speed. the mk 1 is un restricted the barrel is 21 break horse where as the mk 2 and 3 are only 12.5 break. I have a mk 1 but i have a mk 2 engine in it. when i bought the bike it had the mk 1 engine in it and i had 90 in 5th. i was clocked last week at 85 mph with the mk2 barrel. the only thing that i have done to the motor is smoothed the inlet ports and i am running it with a micron can. Alex Flesch