I agree with not following the ACA route in Washington. I have lived in the South Puget Sound area my whole life, and I just don't see why ACA has you go through Shelton and down through Centralia. No offense to those that may live in that area, but its just not a good fit for this tour. Also, HWY 3 is not somewhere I want to be on a bike, let alone a car.
I'm leaving in June and following the ACA route, except for this portion (and Lost Coast):
(my route in red, ACA in black)
I'm heading northwest from Port Townsend, then following 101 or 112 through Forks, then down 101 to Westport. It may be a little wetter, and add a few miles, but its a Pacific Coast tour for pete's sake!
Also, I'm giving myself 45-50 days to do it, which will allow me to take my time. I am shooting for less than 40 days, but leaving some room for leeway since it will be my first tour. Anyway, good luck!