I usually use a dab of antisieze on reciever (a little goes a long way) and start torque at 35ft-lbs. I then check alighnment with gas tube holes, if one lines up I run it there, if not, I torque till one does making sure not to go over 75 to 80ft-lbs.
I use an electronic torque wrench so it is real easy to check torque, but it is expensive (good thing it has other uses). A good old fasion bar or lever type will work too, just keep an eye on the pointer and dont go over 75 to 80ft-lbs.
The reason for antisieze is to keep the nut and upper from galling. It is the best thing I have found, we trust it in high stress areas on heavy equipment, and it wont burn off or turn liquid as easily as grease will, and if you ever need to remove the nut, it will come off as easily as it went on.
Only thing about antisieze is that it will spread all over if it is not used sparingly. One drop will spread a quarter mile.
The set up D tech uses sounds like an awsome way to go also, may have to check one out.