Yep, you have a 70-71 hood so none of the holes in the frame are the ones for the scoop that you have. They are all for the 70-71 two scoop set up. You should also be aware that 72 hood hinges are different than 70-71 and I don't think you can mix them, so if you want to use that hood on your 72 you also need the hood hinges for a 70 or 71 or I don't think you can adjust it correctly. looking at the studs in the picture of the bottom of your scoop in post #25, they are NOT in the location for the stock 72 hood holes anyway, so its probably a good thing that you are starting with a flat hood. The one you show has four studs across the bottom instead of 3 and no center stud in the front.
I would take a grease pencil and put a line right down the middle of your hood. Put some ribber vacuum hose nipple plugs on the studs, so you don't scratch the paint. Get it centered in front, and then center the back by measuring from the back corners to the outside edge of the hood. You want to pay attention to where the studs stick through so you don't hit the frame underneath in a bad location
