Don,
I just discovered this thread! Seems like I remember you starting this project on a different thread and I was waiting for updates. I was beginning to think you had been sidetracked like me...

Anyway, back in the early 70s I had a '68 Olds 442 with the 400 engine. It started smoking and I decided it was time for a major rebuild. While I was having the block bored and the crank ground, the machinist talked me into splurging for a balance job. He said that Olds engines had some of the beefiest bottom ends of any engines made and they, therefore, are notoriously out of balance. I finally agreed to let him do the balance job on it and I was not disappointed. It made the thing run as smooth as silk even with a lumpy sounding cam. Improved acceleration, too. If the extra $$$ won't break the budget it's worth it...