Nothing special sticks out in my mind. Use some WD-40 to make fitting the different pieces together easier. As far as a torque spec for the head flanges. i have always tightened them like i do everything else. It would be pretty difficult to get any type of torque wrench in that position anyways. Just snug it good and tight, complete the rest of the install, and then check for exhaust leaks at the flanges, if you have leaks you may need to either tighten the bolts up more, or re-center the flanges over the exhaust port, make sure you have the copper gaskets seated properly.
Bo