I recently installed my AS&M headers and I notice a tick coming from the engine now. I don't think it is an exhaust leak because I do not smell any exhaust fumes in the engine compartment. Do they normally have a ticking noise? I tightened up all my bolts today...

 

If the tick increases in frequency with RPM's it almost definitely an exhaust leak. I had one after I first installed my MAC's and I had to tighen down the bolts a few times after it went through several heat cycles to get them cinched down really well. One trick that I found one to use a piece of tubing and with one end up to your ear, move the other end around your header primaries (or other joints in the system), and you will be able to tell where the leak is.

Also, some header gaskets are more forgiving than others, I used Fel-Pro's instead of the copper ones that came with the kit, and they turned out great once everything was properly torqued.

 

Sounds like an exhaust leak to me. Track it down and seal it up.

Dan

 

second that, right after my install I had the same thing, sure enough it was a leak

 

I really don't know if it is a leak, it doesn't seem to increase with RPM but actually seems to dissappear. Does the fact that I don't smell and exhaust fumes in my engine bay give me reason to think that it may not be an exhaust leak?

 

Sounds like an exhaust leak--something I know all to well . It's been almost a year now since my LT install and I'm still dealing with the notorious "ticking" sound. Here's what I've done:
1) Started out with Percy's aluminum gaskets--had 3 blowouts on one side, 2 on the other (car ran horribly).
2) Changed to Felpros and sprayed both sides of the gaskets with silver high temp spray paint--PS still holding good, DS started ticking 3 months later (1 blow out).
3) Just changed the DS out with another Felpro but now put copper RTV on both sides just before I installed it--appears to be holding up quite well. I've used copper RTV on other exhaust connections (y-pipe, slip fit) and it hasn't failed me yet.
Each time I've "fixed" my leaks, I've noticed the car performs MUCH better--just goes to show how an exhaust leak before the O2's can dramatically affect performance.
As for smelling the exhaust--if it's blowing out from below the header, you may not smell it. Pull your plugs on that side of the motor and see if any are brown on top--mine were! Also, you can get a rubber hose and use it to help pinpoint the ticking. Good luck....