Front pipe flange warped?
 

I purchased this front pipe from a local manufacturer, and was about to install it when I noticed one of the flange looked funny. So I checked with a straight edge and it appears the ends of the flange is bent outwards, but the area around the pipe hole is flat.

At first it doesn't look too bad, but when you place the straight edge flat against the bolt hole, it really magnifies the amount its out of shape.

Should this be a concern, or will the ends be "pulled" in once fully tightened?

http://s27.postimg.org/p4fv66i0z/image.jpg
http://s27.postimg.org/moe1sbzyb/image.jpg

I bet you'll be just fine with that. Should get pulled together, and the gasket will have extra pressure right where you want it I would think.

I'd use good high grade bolts/nuts and use anti-sieze as well.

I'm not an exhaust expert, but that looks OK to me. I'd try and run it if it were mine.

Completely normal, flanges don't need to be perfectly flat to fit correctly

They "should" be flat if its bolted to fixture when welded and then surfaced after. However with that said the actual sealing surface on that flange isn't too bad so i would bet you'll be fine.