Oaked Imperial Stout kit - dry hopped?

I recently purchased the True Brew Oaked Imperial Stout kit from my LHS. The owner told me it was his favorite kit by TB so I went with it. As I was picking his brain about it I got a wild hair to dry hop it to add a little bit of a hoppy after taste to the malty/oaky/chocolatey fore taste - so I decided on an ounce of Fuggle Hops. The kit says to add the oak chips after about three days of fermentation, my question is: when should I add the hops?

Primary? Secondary?

And how long should I let the hops sit in the carboy in order to acheive enough of a hoppy flavor for it to be noticed?

Thanks in advance!

I'm guessing that this is a high grav. brew? I've read and heard some things about dry hopping. First: If you don't use two Oz of pellet hops then you are wasting your time(and hops). Second: you should use a high AA hops and don't had hops until it is finished fermenting because it is a great way to introduce bacteria in to your beer. I also have heard that the darker/higher grav. the brew the more hops is required to get much aroma or IBU. hope that helps.

Thanks! I appreciate your response.