Cracked fuel bowl?

Hi all!

I'm attempting a carb rebuild on my Edelbrock 1406 for my 70 Mustang. I suspected the carb was dirty because the car was running rich, the idle mixture screws seemed to do nothing, and I wasn't able to get the idle down below 2500-3000 RPM.

After disassembling the carb, it was dirty, but not as bad as I expected. It was mostly full of little particles, almost like sand. These particles clogged the passages and internal filters enough to cause problems, I would think.

I also noticed what looked like a crack in the right fuel bowl.

http://i215.photobucket.com/albums/cc93/anothersmith84/Mustang/7fuelbowlcrack.jpg

But if you look at the front right, there's a "tube" that runs up and stops just above the PCV valve. I figured that it might be designed to drain into that "tube" for some reason.

http://i215.photobucket.com/albums/cc93/anothersmith84/Mustang/1inEngine.jpg

What do you all think? Is it a crack, or by design?

Also, I'm a newbie so... be gentle

No crack

Just in case anyone has the same question in the future... I took the carb to a shop that rebuilds carbs today. He said that the "crack" is by design and showed me another Edelbrock with the same "crack". It pushes gas through the passage on the front and out the jets on the top.