H pipe install question

I did my first Mustang upgrade yesterday. I bought a summit racing H pipe and the fit and finish were good(except the bolts were too small) but can someone tell me how to get the ford flanges to align properly? Last week, I tried to make my own h pipe(too many bends and no pipe bender) and when I realized I would need to buy one I had trouble getting the header and pipe flange to seal properly, even on the stock pipe.

Now I am having the same thing again with this one. Is this common with Mustangs?

Ohh, by the way...Pics of the install coming soon. One a side note, I did A LOT of mods to my Firebird and never took any pics, so I am making a point to take pics of just about everything I do to the stang.

Thanks for the help!

OK, thanks guys. I like the design better, cause I wont be going through gaskets once every other month.

As promised, I posted pics of the install, but I did it in my new cardomain page. I think it also has a link to my old Firebird. I miss it!!!

http://www.cardomain.com/ride/3839387/1

I retightened the H-Pipe a few hours ago and saw that I was missing a header bolt. I replaced it and forgot to put the plug wire back on....I'm surprised at how well it ran on 7!!!

I found a small leak on the same header so that, the smog and AC delete is next!