Internal balanced

Tom is right on all counts.

All the late cast crank engines I have torn down
have the 6 pack rods (908 number I think).

Nothing wrong with a Cast Crank and either of the rod
designs in a street/strip kind of car.

However, for the couple hundred bucks they cost, I run
the steel cranks.
I couldn't get lucky like that all 3 of my late 440s are ly rods