How big to make the hole in the hood?

I would like to guess yet but I havent done this kind of job on my car yet. My actual plan was to mark out where the scoop would sit with pencil or chalk or some other temporary mark on the paint then cut out what you have within the outline (roughly .5-1 inch of clearance all around) and just drive around a block or 2 away in circles with the air cleaner sticking out. If it looks too close then the air cleaner should only contact the hood a couple times before you have a chance to get home and trim more