As you will see from other threads, after the bush is fitted it has to be reamed for alignment and also to the size of the crank journal. Its best to have the journal re-ground only just sufficient to clean it up.
The clearance crank journal to bush is 0.0015. [or 1 1/2 thou].
The OD of the bush is sized to press nicely into the cases when warmed, if the housing has worn, bushes with larger OD's can be made.