Speaking of just 5 bolts, it would be sweet if you could put a 100 series drive flange on an 80- that would be a nice upgrade, to what in my experience was a bit of a weak point. the bolts with the cone washers are 10mm- takes a 14mm socket to remove, so they won't strip as easy. Those pins are bigger too- I bet you could mill out an 80 hub to retro fit... I still don't like just 5 lugs, but I do like the bigger drive flange bolts, and yes there are 6 of them.
Oh, and the star washer between the big nuts is the same. Same nuts too, for that matter.