Another trick is to take an inspection mirror and angle the mirror towards the exhaust (about 45 deg. you still need to see it) as you pass over the manifold any leak will show a vapor trail across the surface.
Thanks guys and girls. The bolts shouldn't be to hard because I had the whole head off a couple of months ago to put new lifters and push rods in. I do plan on replacing them with new bolts while I have it apart. It's looking more like next weekend before I will be able to get around to it now. The rear passenger side steel brake line had some rust on it, and late last night on my way home, it decided to burst and leave me with almost no brakes. Right now that is at the top of my list to get fixed (in the middle of doing it right now), because I HAVE to drive the car about 300 miles TOMARROW. I have drove the car over 150 miles since the noise started, and it dosen't seem to be getting any worse. Right now it is just a minor annoyance, and dosen't worry me as much now that I know the engine isn't just going to blow a rod or something while I'm driving down the road.
Dude i feel your pain for many years my mav has been primary transportation as well as "project car". your perseverance is outstanding. i too have found myself in many gotta fix this so i can drive this tommarow or gotta upgrade this in less than a day so i can work tommarow. I have also rushed through many things that i wished i hadn't (and caused myself more work/cost later). but ya gotta do what ya gotta do. best of luck.
From what I head, I also believe its just an exhaust leak. 6 cyl manifiolds will warp slightly over the years because they are long and thinner than 8 cyl ones. If they do, they eat gaskets like crazy. If you have a machine shop or know someone with a long table belt sander, pull the manifold and true up the surface before you put another gasket on.
Another old trick is to use 2 gaskets. If you use a header gasket instead of the metal type, you can also soak it in water and let it get soft before you put it on, when the engine heat drys it, it will conform to the manifold and head better. Just remember to snug it down after it drys out. I've done this many times with headers that wouldn't seal and it worked every time.
