Graymist, I used to run that road all the time up till 3 years ago, winter & summer. The best advise I can give is pay attention to the speed limit signs...DON'T exceed them! Sikkani Cheif is not that bad but is posted at 50 kph for trucks, DO NOT EXCEED IT! There are brake checks before every steep hill above 6%, & I seem to recall Sikkani being 8%, make sure you use them, as it's against the law to bypass them, even empty. There are a few good swithbacks along there, nothing really major if you keep your head about you...
I seem to recall on that is worse than Sikkani, but for the life of me can't recall the name of it, maybe Lady North or COLT can help me out here.. Pink Mountain & Steamboat are 2 that I can recall, but maybe they are further along the route to Whitehorse.
Best advise is to take your time & remember the speed postings are for CARS!
BC is famous for a 30-50 kph corner at the bottom of steep hills, so just take your time & remember one cardinal rule about the mountains.... go down the hill in the same gear you crested it & you should be fine...in other words it you got to the top of the hill in 5th gear, that's the fasted you should go down in. And always be aware that with Super B's you are grossed out at about 140,000 lbs pulling 2 trailers, try to stay off your brakes amuch as possible & if you have to brake do it well in advance using steady pressure, don't fan or pump them, use youor jakes as much as possible & take your time. Nobody is going to fault you for going slower, but if you go too fast nobdy will be too happy about scraping you off of a mountain pass OK?
Be safe & take care out there