I've ridden over Carson Pass (8574 Ft) on the Western Express route which uses the Emigrant Trail for much of its climbing past Placerville. At the end of that trail, you join Highway 88. My recollection is that the Emigrant Trail was all up. Just past the junction at Highway 88 there is a big dip down to Silver Lake and a hard climb back up to Carson Spur. From there, it is an easy incline up to Carson Pass.

I did the ride from SF (Vallejo, really) in 4 days to Carson City (SF - Davis, Davis - Placerville, Placerville - Kirkwood, Kirkwood - Carson City). Remember that Sacramento is essentially at sea level. Placerville is 2000 feet of elevation and a tough day. The Placerville to Kirkwood leg is outrageous, the hardest day I've ever had on a bike.

When I did the route, I left my camping and cooking gear at hope in an attempt to save weight. I'd recommend against that and take an extra day, if need be. All along the Emigrant Trail there is forest where you could easily walk a few feet off the road and camp for the night. If you'd like pictures of this trip, check out my trip journal. According to my notes, the ride from Placerville to Kirkwood, though only 6000 in elevation is a ride of 11,000 of gain. I got those numbers from Delorme's mapping software but have no idea if it is correct.

I have mapped a route from Sacramento to Colfax (on Highway 80) staying off the highway. I don't know if you can ride on Hwy 80. It is not something I'd want to do, even if it was allowed.

Good luck!

Ray