Internal or External balance?

Is a stock 454 MK IV with a cast crank internally or externally balanced. I thought they were internally balanced because all factory 454 balancers do not come with an external counter weight. Somebody else told me they were all externally balanced. Anybody know the answer?  

Yes, all Mk IV big blocks were internally balanced.

Your friend's probably thinking of the 400 small block, which was externally balanced, unlike the rest of the small block line which is internally balanced.  

The mk IV 454 were accually external balance from the factory.  

Thanks for the updates guys. Not to ask a stupid question Pontiacman8 but can they be internally balanced at all?  

A repetable machine shop can internally balance them.