FWIW, I don't think an 8 weight would be overkill. However if the
pinks are smallish, it *would* be overkill.

See:
http://hometown.aol.com/davplac/Alaska18-Aug04.html

I regularly use a #8. These fish average 4 to 6lbs and 7 & 8lbs are common
plus the rivers are strong and wide. Often it's not a matter of the size of
the fish but the line and the fly.