I don't if anyone has taken a look at the interactive PCT map that is using Halfmile's GPS data. (From what I understand, he and some others carry pretty sophisticated mapping/GPS data along the entire trail.)
What's cool is he has very specific waypoint data - including precise mileage - for the Whitney trail. Even better, you can also get a precise guide if going in from the PCT/JMT via the backdoor.
http://www.pcta.org/discover-the-trail/maps-and-guidebooks/Just click 'full screen' and zoom in. You can add all sorts of overlays, including the original ruler & calculator derived FS trails.
