Sounds like you will need a new crank. If the dowel holes are elongated
there is no way that the flywheel will stay locked in place no matter
how much torque you put into the gland nut. The problem will occur
if the first time the gland nut is put on the gland nut is not properly
tightened. At that point the elongation process begins. Sorry for the
bad news. If you had someone rebuild the engine for you, I would suggest
you bring it back to them and have them put in a new crank. If you rebuilt
it, I guess you are S.O.L. and will have to make a major decision regarding
your bus.

Ric