Why does Edelbrock cut some plenum dividers and not others?

Right now I've only got a 670 street avenger. I think I'm beginning to reach its limitations. I wouldn't notch the intake until I got a double pumper.

It'd be interesting to try. Don't want to trash a $250.00 intake if it doesn't work out. LOL

With the stock hood, I don't know if I have room for a spacer and an air cleaner that's of sufficient size. I'd like to get at least a 1/2" for the heat isolation though.

Steve