I had a purple 73 H2 and it would almost fly. I went from stock to a set of J&R chambers then to boring and forged Wiesco pistons with .125 cut off the intake side, extensive transfer port work, the exhaust port raised 2mm and widend the same amount and put on a set of Denco chambers. I used a 48t rear sprocket also. It would pull a wheelie hitting 5th gear at over 120 mph. What a wild ride!