There's a difference between engine math (which I understand) and it's effect on performance (which I don't always) and I think the performance part is what you are after. Lunati has a nice explanation of what it means in terms of performance on their tech site. Link below.
http://www.lunatipower.com/Tech/Cams/CamSpecTerms.aspx
BTW: Those block photos you sent Brian were helpful. Now I understand why I cant easily run stocker heads on my M6010 block.