I have the Haynes manual just for torque values but it is lacking on anything to do with exhaust. I'm replacing the exhaust flange studs and nuts. Looking for torque values on each.

1996 F150 with 4.9 I6.

 

You just put the stud in tight enough so it won't vibrate out. Then you install the y-pipe and tighten the nuts; so that they're tight. You're not trying to see if you can snap the studs, you're just making it tight.
Never saw anybody use a torque wrench for those; but I suppose it would be about 35 ft lbs, if that.