440-8

It's the 8th "incarnation" of the core box the block was cast in. "-1" would be a fresh core box. As it was used, there would be revisions and touch ups to allow it to keep being used. It doesn;t mean 8 blocks came from it - but it was changed 8 times during production casting runs. When you combine that with the poor casting quality of Mopars - it doesnt mean much.