Balance

[Bruce Edwards]

Most Fords are externally balanced. That extra bit of steel on the flywheel and the front balancer are what you see on an external balance. An internal has all of the weight on the inside. So the flywheel and balancer would be with out any weight.
In this case the crank is drilled and heavy metal is added to balance the rotating parts.
The best way is to balance it from the inside. The cheap way is the outside. The factory can spin the motor and drill the balancer till the engine is in balance.
The best way is to balance the rotating mass is to spin the crank with weights that match the weight of the rods pistons and rings after these items have been all balanced to the same weight with the rods being balance for the same weight on both ends.
The 427 NASCAR crank has to be balanced with the weight of the oil figured in as it has a hollow crank pin.
Just want to throw that in.