RUN- - - -DO NOT WALK, TO ANOTHER MACHINIST!

This guy is about to make things horribly worse! At this point, line boring is the only reasonable solution. Be sure the machine shop that does the line-bore remembers you've got timing gears, not a chain. If they take too much material out of the block while doing the boring job, you've got a boat anchor- - - -no way to correct timing gears that are bottoming out!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!