8 bolt crank flange

there is often an extra hole ... no threads to index the crank during grinding ...

I have seen many welded up and changed to 8 bolt, with one missing because the stock cranks had a big notch were the eighth one would go (that makes it 7), they do this to use the good racing clutches that only come for 8, and if you are making a stroker (welded up) from a stock forged crank what is a little more welding.. old school racers did lots of wierd stuff.. now you guys can get a new stroker crank , alum ported heads for peanuts compared to good ole days