If it shows no signs of bottom end problems, I don't think I'd worry about it. Many of us here are well over 200k and bottom end failures on this engine are almost unheard of. I'm surprised they even had to have the heads "done."

You also mention "the trail," so I'm guessing you don't really need to worry about getting another 100-200k out of it...? AFAIK, bottom ends will generally give you some warning before leaving you stranded.

However, if/when the time came for a "rebuild," I'd probably just get a lower milage (I'd even consider 100K on this engine fairly "low") long block from a junkyard and drop it in.

Just my two cents...