I can't forget something I don't yet know of.

I've seen no reference to "16 or so planes already in the fleet with Heart." What is your reference for your numbers?

[I'm really not trying to be argumentative -- I'd just like to see a source for correct information.]

Also, assuming your numbers are correct, and there will ultimately be 114 800s with Heart and 82 with Evolve (by sometime in 2018), the percentage of 800s that will have Heart is 58%. So yes, 58/42 odds are higher than my initial guess at 50/50, but not by that much.