Well I've been hearing my headers leak for a while now and finally got under the hood to tighten down the bolts, thinking that would fix everything. Well they were all pretty tight, but when I got to the last one - the back one on the drivers side - the bolt isn't there. I get my mirror and in actuality the BOLT is there, but the head is gone. It's in a difficult spot to just tap and remove, so I'm wondering if I'm in danger of blowing the gasket out or if it will affect the truck performance wise or in any other way?