in my opinion if someone is concerned about flat tappet cam break-in then don't use a fast rate cam; simple. the faster the ramps the more spring that is needed to control the valve train. more spring/ramp speed means a greater chance of scuffing. i seriously doubt that the old factory engines did a break-in procedure, but they never used the ramp speed that is used today. if fast ramp speed and high lift are a must then use a cam that requires a tappet with a wheel on it.