I recently had recently had to replace my exhaust on my 78 the problem comes when I got the new exhaust its off of a 79 limited which I knew there would be some mounting problems. I attached everything and made sure it was snug and when I started there is an insane leak coming from the collars where headers and engine meet I am ordering replacements gaskets, should I order new 79 collars as well or could there be something else? You can see where is leaking in the image