Ok, new to this site but not to the CB world. Heres my question: I have a 71 750 and want to put in a big bore kit...but do i have to rebuild th entire eng.?? or just the top end? if just the top end what about the conecting rods, balancing the crank for the larger pistons, bareings, and so on... what i want to do with the bike is race it at the salt flats and see how fast the old girl will go...I live in S.W. Colorado and if any one know a good if not great engine builder would be sweet. your question and comments are welcome. thanks-mike