That is kinda what I was on about.
However, when a cam is ground, material is removed from the base circle. When you have increased duration, the ramp is changed. This means that the valve opening (or the "event") may occour sooner.
What is done in i this instance, is true tdc is found (there is about a 10 degree dwell period at tdc) by turning the cranshaft one way untill the piston reaches the top of it's stroke. A marknis placed on the pulley . (or degrree wheel)) tThen the crank is rotated the other way untill the piston reaches the top as well. Another mark is put on the pulley. The point halfway between theese two marks is exactly tdc. Then you set up a DTI in a magnetis base on the block deck, with the pointer of the DTI iin the cup of a pushrod. turn the cam srocket untill the lifter is on the back of the base circle. (No lift) Then zero the DTI. There are a few ways of doing it from here.one way is to wind the cam around till the DTI shows peak lift, and the rotate the crank till the degree wheel show the number of degrees at which peak lift occours on the cam specs.

If aftere doing this, the dowel hole lines up, then your cam is said to be "Straight up" . Depending on how much meat has been ground off, you may get away with this.

A buddy of mine, had a full race A12, with a mega lumpy cam. It used to pull to 9500. But when he dialed it in, he had to advance it buy about 13 degrees.