If you drop the front you are lowering the top speed due to the engine revving higher. He will want to add to front and reduce the rear to get more top end (in theory). As mentioned, adding top speed without engine mods is not likely through simple gearing.
If you go -1 up front it is the same as +2 at the rear. Opposite of what he wants.
Misread! Thought you meant not making any changes at the front and only going for the rear. My bad. Also yes, larger @ front.