i have a friend that did a 100+ hp shot on his 80 kz 1000. let me tell you, that thing took off. but it only took off about 4 times, then BANG!!!!! it came apart, badly.
he used it for street racing all of the time. had a 200 tire with a 6 " extended swing arm, and he could light that tire up in 5th gear with no problem. he can build good engines, many of his friends have his engines in their bikes. i had one before. very strong runner. i have seen one of his bikes keep up with a hayabusa in the past.
i would honestly say that if you have big wevo's. go for it, but you had better build the engine for it. just slapping a shot over i think 30-50 is asking for a hole in some thing like a piston or block. and if you do not have ALOT of time on a bike with that kind of power, i say do not do it.
just a note , my buddy is now building a monstor kz engine 1400 something, with nitrous, he only street races now, and he goes for money. not me. i stand on the side and watch people loose there money and their bikes. then ride home in one piece. !!!!!!!!!!
just my 2 cents!!!