The '05 Speedmaster would take it better, because it's cammed more for low-and mid-range torque than the America is, so it could take a 17T front better and without too much of a loss of pick-up, and maybe gain a little more top end. My riding style dictates that I stay with the 16T front with my '03 Speedmaster, especially since she has cams in her from the dealer, that have undoubtedly taken a little from the bottom to give to the top.
