I had one of those W body store IC's and loved it. Have you put water in the core to see if it leaks or if that's just a line from where it was made?

On the bend.. I'd try and have that fixed/flattened. don't worry about that gap at all. Won't effect performance. If you want though..rough up the sized a little and fill it with RTV once the core is back in. Honestly though..I wouldn't.