They are locator pins in the center on the front and back of the block, you'll see them if they are still there.
Your intake may have holes in it on each end already, some do not. If yours doesn't just grab the little pins with a Vice Grip tool or something similar, and twist and pull, they pop out.
I usually make sure there is a rag in place just in case you lose it, so it doesn't fall in the valley..
