Malossi sport 112cc conversion


What do i need to do to fit the Malossi sport 112cc kit on my pk50xl ?..

I have splitted the case and going to change all bearings and worn-out parts.

Want to use a racingcrank. but what type? 

Are the bearings the same size on a racing crank that it is on an original one?..

And what other parts is recomended for this conversion?..