I've had tight connections in DFW before the NRT flight as well...it does make for a nail-biter if your flight to DFW is late.
I'm curious as to people's thoughts on this myself----Should the OP just go ahead and snag the "later" DFW/NRT flight, just to be on the safe side??


If he/she end up with "extra" in DFW, the A/C's have plenty of options (if they're in J): just get to the airport in BOS & finish the "morning routine" at DFW, grab a shower, go for a run or climb in the mini-gym in A (good if you're about to sit for many hours transpac), decent food offerings in D, etc.