Mission accomplished, and Oh, does it run sweet now!!
(It did run a bit rough at first until the computer reset itself.) I'd thought it was still running OK before doing this, despite the check engine light, but it clearly hadn't been.
I was really worried that something would go wrong, since this was the first time I've ever taken a fuel rail off. There was a lot of trash down around the bottom of the injectors, too. Fortunately, they all detached on the top end, but I worried that I might have gotten some trash into them anyway. Carefully cleaning every bit of the old gasket off the surfaces took as much time as anything. I couldn't find my gasket scraper, but a large flexible kitchen knife did just fine. And much as I anticipated the possibility and tried to avoid it, a socket dropped into an intake port, so have a magnet on a rod handy or shove a paper towel into each port as soon as you can.
Before getting the rail back on, I took an old glass syringe and 21-gauge needle and flushed each injector out with gas, hoping to blast any particles that might have gotten in there out. No telling if any had, but it didn't seem like it would hurt. (If you try this and only have a plastic syringe, make sure the plunger doesn't swell/dissolve in gas first.)
Then getting the rail on, I Vaseline'd the O-rings, and swabbed the ports on the rail with 10W30. To some surprise, the first side popped together pretty easily, but with the first side I had fairly full freedom of movement to align the injectors with the holes. For the other side, tho, this left the injectors at an angle vs. the holes. But by shifting the rail toward the other bank, past the position it would eventually sit at (so the injectors would be more perpendicular to the holes) and giving a gentle bump with the rubber end of a hammer handle, it popped on too. Hoo-bloody-ray!
For torquing the studs following the pattern someone kindly posted near the start of the thread, I first took all to 60, then 90, then 110, then 120 INCH-pounds. Then I waited and came back to re-torque. I think I did this at least 3 times before there was no further movement on any stud. No problems with snapping any torx head. Remember - 120"-lbs is 10ft-lbs! I re-checked the torque on the plenum today, and there was only a very slight shift on one nut.
BTW, it occurs to me that if you do snap a torx head off, there's no reason why you can't just lock two nuts together on the stud and torque using the top nut, then de-lock them. It'll take awhile to do it that way unless you have enough nuts to do all six studs, but probably way less time than it takes to go to the dealer for a set of new studs - you don't need the torx head for anything later. I don't understand how you can snap a head if you're using the right torque setting, tho.
The only other thing of note is to make sure, while getting the plenum on, that you get the O-ring on the EGR tube seated to the point that you can't see it anymore.
I hope this may be of some further help. I'm extremely grateful for all the help I got from all the posts above!
