Exhaust Leak

Hey all... Got my new cat installed, but can feel exhaust leaking out where it connects to the factory head pipe (down pipe?). I cranked the clamp down so far that even if it would move, I'm afraid to do any more. Should I try adding another clamp closer to the head pipe (there's an inch or so of room), or just get the thing welded?

Weld it. If you overtighten the clamp anymore and crush the pipe, it may leak even more...

Cory