440 Harmonic Balancer Timing Marks Off

when a cam is degreed in, the timing cover is off! some folks say degreeing in a cam is a must, it is not. it is a good idea when you are done installing the cam, and it is at top dead center, slide the timing cover and balancer on to check the timing marks. do you know if the timing cover and balancer are from the same year? if you are sure the #1 piston is at tdc, the timing marks are off