I would not recommend Hwy 36 unless you are driving a sports car or motorcycle. Too many tight curves. Hwy 299 is doable but has 5 mountain passes you have to climb and descend, but is the better choice of the two. Count on 4 to 5 hours to drive 299 from 101 to Redding. If you are going further South of Redding I would recommend from Eureka that you take 101 South to Ukiah and catch Hwy 20 over to Williams and catch I 5 to continue south, but if you are just ending up at Redding, 299 is your best bet, stay away from Hwy 36 is my recomdation.