when I started my truck this morning, I heard what seems to me, the sound of an exhaust leak coming from the drivers side front??? But, when the truck warms up, it's gone. Help.. any suggestions...

Sounds like one of the header bolts is lose. Most likely the one close to the fire wall. They will all look tight, re torque them to find the lose one.

do you know what I should torque them at???

I have no idea, I had my mechanic do it....I just wrote up the list of things to do.

Ask PhilD, I think he would know.