Whats wrong ?????

No I'm sorry Should have mentioned... Its a Edelbrock Performer. Took it off my cracked 360. Doesn't look milled but How would I know?? And NO the rear pin is gone and theres a hole for the front pin that I put there.Can you really double gasket it??
AND whats this hole?? I've never noticed it on other engines??? Again this is my FIRST engine build!
And this is my Stock manifold notice it fits nice. What do I gain with a edelbrock manifold over the stock???

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duster 116 (Small).jpg

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