I doubt leaking will cause bluing you'd more likely hear it leaking or you'd still be getting soot at the leak. Make sure you tighten the nuts evenly as you run them down and torque to required value.
Alright I'm going nuts now. I can still hear a slight hiss so I did the dollar bill behind the pipes and it sucked it in!! Does this mean I have a burnt valve or is this still the leak?
You could do a compression test and see if it holds pressure or if it bleeds off. At 27k there should be no reason to drop a valve unless you have a weak valve spring.
I've been trying to get time to check it out but I'm in on emergency call back and a 24 hr shift just turned into 48 hr so I got time to look for things to check Monday