I am a scrawny dude just starting to lift weights for the first time and follow the primal blueprint.

What is the upper limit on the changes in my weight and measurements can I expect over the next 12-18 months? I am assuming that I will eat correctly, exercise, and rest as Mark prescibes.

Currently I'm 6'2" 165 lbs, Chest 37", waist 31"

I don't plan to "bulk up" in any way, just add as much muscle as I can to increase strength and keeping my body fat roughly the same. I'm at ~10% now.