Perhaps "nuts" is too strong of a term. Have you done any other climbing higher than Mt. Whitney? Have you done any technical climbing? Do you know how to self-arrest with an ice axe? Can you get yourself out of a crevasse?
You might want to start with some less-ambitious climbs -- maybe even Rainier. There is a big difference between walking to the 11,000 foot level on Rainier and climbing to the summit. But if you are already skilled, and you have all of the equipment and you know how to use it, then Denali might just be within reach.