How to determining what cam is in a motor

I would think that if your damper is marked accurately enough, you could use the same run out gauge to figure out the duration and LSA. Put the gauge on the intake valve andmeasure how many degrees the crank goes through while the valve is moving up and down (or from .050 to .050). Do the same with the exhaust and you've got your duration on each. Put the gauge on the intake, move the crank to max lift and switch the gauge to the exhaust .Turn the crank to max lift on the exhaust. The difference between the two points on the damper is your LSA. The biggest problem I see is the accuracy of your markings on the damper and how well you can accuratly read them in relation to the pointer.

This is just a WAG, I have no idea if this is practical or not. I'm sure others will chime in on what might be wrong with this process. I'm actually curious if this IS workable and if anyone has tried it if it is.