It's a N55 motor. If I had to swap the motor, is it an "easy" swap, or are there a lot more issues linked to the DME system, like the injector flow rates, etc that are going to bite me in the butt at start up?

Of course that brings another point into play. The engine and transmission have 205,000 miles on them, so popping in a 90,000 mile motor and hooking it to the 205,000 mile transmission might not be the smartest thing either, maybe forcing me to put a newer motor and transmission in.

I think I'd like to try and get the head off and replace that in the car, if possible. That's the easiest, but now having ever taken an overhead cam head off, the thought of it is concerning because of getting it all timed back up right, but I assume there's just a procedure to go through and then that'll be all set.

I haven't found a video on pulling the head in the car yet, but I'll work on my searching a little more today.