fattest cam in a 340?

well in the spirit of keeping this thread alive, imagine this is your motor: you buy it, give it some tune up stuff; oil, plugs, wires, cap&rotor, ignition box, etc.

you go to hit it with the timing light and you see nothing.

you look on the balancer and clearly see a mark on it.

why would you not be able to see the mark, what do you do about it?

all the info you have is that it has some sort of aftermarket cam in it.