Is the 440 cast crank harmonic balancer the same as the one used on a 400 cast crank engine?

Nope. The 440 one is considerably bigger.
I have one of each here; if I can find 'em I'll post a pic.

Thanks for the reply and I'd appreciate a picture of the 400 balancer if you have one. I have a 440 cast balancer and it has "440 Cast Crank" cast into it so that's why I asked.

Here ya go:

One more:

Thank you. Obviously the 400 balancer is a fair bit thinner than the 440 one I have.

Thanks again

However, the cast crank 383/400 and the cast crank 440 have EXACTLY the same amount of unbalance. The dampers will interchange functionally. I don't understand why there are different dampers.

R.