I have a 1972 CB750-K2 engine I'm rebuilding. I've run into a problem with one of the bearing seats in the engine case being distorted beyond the specified size limit. Machine shop says it could be re-bored, provided I can locate a correct over-sized O. D. bearing to put in there. Is anyone familiar with this issue? Is there any solution available? (Note issue is with crank bearing seat #1, next to alternator end of crank)