the Busa handles like a dog compared to shorter narrower bikes. Putting a 6 cylinder into a bike will make it handle like crap. Why do you think jap bikes got kicked in some forms of racing by the other manufactures.... V-Twins. Bike is thinner. Crank shaft is half as wide. Makes a bike HUGELY flickable. Its all scientific shid,but the enertia created by a crank long enuff to have six holes hangin' off it will not be good for handling. The Honda CBX made for 2 yrs gone. Kawi tried it too. They ended up at the strip. How are you gonna lean that crud over. It would put about 216 cc's in each hole, so even with a super long stroke(which decreases the revs a motor can attain) the thing would end up too wide.
just an opinion....flame on