I agree with FRANKR, your miles per day estimates may be very optimistic. The coast especially during the summer can be a slow road with all the retirees driving their 40 ft. RVs while gawking. Since they take up both sides of the road you will go miles without a passing opportunity. However it gives you time to slow down and gawk right along with them.
If you are planning to end the trip in Crescent City I would suggest taking a few hours and hitting Oregon, just to say you did. If you think time will be tight go north on 101 and south on 1, much better view of the coast that way.
San Luis Obispo, Monterey-Santa Cruz-Half Moon Bay, Ukiah and Eureka are good stops going north, add to that Fort Bragg and the San Simeon to Morro Bay stretch on the way south. Motels get filled up by 6, plan on stopping by 5 or even 4 just to be safe. Being from LA I don't need to tell you to avoid SF during rush hour. Big Sur to San Simeon only has one, very expensive, gas station at Gorda.
To finish it off I can tell you from years of experience the 101 from Santa Barbara to LA on Sunday afternoon is a gawdawful slow slog as is the other way on Friday evening.
This picture is in Morro Bay.
John in Mauritius
2009 Road Glide in California