Thanks for straightening me out Rooster.  I should have said synchro balanced.  I looked up AVS and now know the difference.  So let me ask my question correctly:  Is the crank without synchro balance as on 220707-0147-99 better for building a race engine than the newer ones with the synchro balance?  Thanks, you guys rock. 

I have a chance to buy three of these and was wondering if they or the parts in them are good for building flathead racing engines? They are model # 220707-0147-99.  If not what would be good model numbers to look for in old flatheads?  Thanks.